Category "Learn About Endometriosis - The Basics"

Please tune into your local CBS station to see Dr Cook on Monday, 12-5-16, on The Doctors TV Program. It will air in California at various times, depending on location.  For those unable to watch the program at the airing time, there will be a post airing video available on our website, our Facebook page, and on The Doctors CBS website.  San Francisco Bay Area residents can view on KRON-TV at 2pm, Los Angeles Area can view on KCAL-TV at 11am.

Director and Producer Shannon Cohn announces the premier screening of her documentary film Endo What? this April 13th at the Delaney Street Theatre in San Francisco.  Please join Dr. Andrew Cook and Libby Hopton, Director of Research & Evidence Based Medicine, as we gather with a group of esteemed panelists to answer questions on Endometriosis, and discuss issues relating to public awareness of this disease. Don’t miss your chance to view this important film which includes heartfelt stories from patients and insightful commentary by world renowned Endometriosis experts and leaders in the field.  Tickets are available on the Endo What? website at

Announcing ~  Special 25% discount on tickets when you enter VitalHealth on the tickets page !  Special thanks to Shannon Cohn for this discount offer for all of our patients and Facebook fans ! 

Congratulations to Director and Producer Shannon Cohn, along with her production team : Patricio Cohn, Producer and Cinematographer, and Arix Zalace, Producer / Editor for this fine production.  We would like to extend a special thank you to the women in this film who so bravely and generously shared their stories and personal experiences. These testimonies have contributed greatly to the core content and are truly instrumental in depicting the impact of Endometriosis on women worldwide.  




Because so few people know that 70% of teens who experience chronic pelvic pain are later given an endometriosis diagnosis, many young women suffer years of pain when it’s overlooked as a potential diagnosis. Endometriosis is generally thought of as unique to grown women and not considered as a possibility for adolescents and teens.

One young woman, Erika, would like to change that lack of awareness for young girls and teens experiencing chronic pelvic pain. Endometriosis Excision Ends Teen’s Years of Pelvic Pain is Erika’s video story of her four-year journey to reclaim her life without disabling pelvic pain.

“I just want other girls to realize that there is hope. You can regain your life. It’s not a life sentence of pain. If you get to the right surgeon you can regain your life and you can progress as a person without pain.”

Erika’s Endometriosis Diagnosis Mission

Erika has “gone public” with her story in the hope of helping other young girls and teens to avoid what she had to endure. Erika’s story recounts the battle she and her mother fought to overcome years of pelvic pain and misdiagnosis to finally reclaim her life.

Erika’s story – and her mother’s story – is a story of resilience and determination to find answers that would restore Erika’s life. Today, after her endometriosis surgery, she is without pelvic pain and living a normal life. Her message: “You can regain your life. It’s not a life sentence of pain.”

Erika had help – her mother, family and a streak of perseverance that finally got her a correct diagnosis of endometriosis. And she’s now just as tenacious in wanting young women and their families to insist on having their physicians consider the possibility of an endometriosis diagnosis in their diagnostic quest.


Endometriosis can cause an array of symptoms that differ from individual to individual and may worsen over time.

What are the common symptoms of endometriosis?

  • Severe pelvic pain: The pain may be cyclical (worsening around the menstrual flow and ovulation) and/or non-cyclical in nature (constant throughout the cycle). Women describe a burning, throbbing, stabbing pain in different parts of their pelvis. This pain can be even more severe than labor pains and post-operative pain.
  • Pain with sex: Endometriosis can cause pain with deep penetration. This is because the area of tissue just beyond the end of the vagina is commonly affected by the disease, making it exquisitely tender and sore.
  • Pain with urination and bladder pain: If disease is present involving or near the bladder this may result in bladder pain/sensitivity and pain on emptying the bladder. Another common cause of bladder symptoms is interstitial cystitis, a condition that frequently co-occurs with endometriosis.
  • Pain with bowel movements: Endometriosis involving the lowest part of the colon (the rectum) may result in pain with bowel movements during menses (or during the whole month long).
  • Pain prior to bowel movements: Endometriosis involving the colon may result in pain just prior to bowel movements.
  • Cyclical rectal bleeding: If bowel disease has invaded into the bowel wall, the patient may experience cyclical rectal bleeding.
  • Bloating: Bloating may result from the inflammatory response to endometriosis involving the pelvis and bowels.
  • Nausea and vomiting: This may be a symptom of severe pain, of the effect of inflammation on the gastrointestinal tract or more specifically could be a symptom of invasive small bowel disease. Acute vomiting can be a symptom of small bowel obstruction, a rare but serious complication of endometriosis demanding emergency medical intervention.
  • Constipation and diarrhea: Endometriosis near or involving the bowel may result in IBS-like symptoms.
  • Fatigue: Severe fatigue is a non-specific symptom of endometriosis. It is a common symptom experienced by sufferers of chronic illness and pain.
  • Infertility: It has been estimated that 40% of women with endometriosis struggle with fertility problems. Around 20% of women in a healthy population will experience infertility, meaning that in those with endometriosis the risk of fertility problems is doubled. Infertility may be due to adhesions that result from the disease process or from the effect of the disease on the intrauterine environment; endometriotic tissue releases chemicals that may hinder conception and implantation.
  • Shoulder tip pain: Less commonly, if a patient has diaphragmatic endometriosis, she may present with cyclical right shoulder tip pain. Diaphragmatic endometriosis is relatively rare.

Importantly, while endometriosis is associated with a range of symptoms the most common symptom is chronic pelvic pain. You do not have to experience all of these symptoms to have endometriosis. If you are experiencing debilitating pelvic pain this is not normal. It is your body’s way of communicating that something is wrong and you should seek the help of a doctor who is familiar with treating endometriosis and pelvic pain.

How do symptoms differ between patients?

While some patients are relatively symptom-free except for certain times of their cycles (menstruation and ovulation), others are debilitated by pain each and every day of the month. Many women experience a gradual worsening of symptoms over time, both in severity and in the duration of symptoms i.e., the number of days per month they are affected. A common myth is that endometriosis only affects a woman during her period – while this may be the case for some women, for most patients the pain affects them both during and outside their period.

Is endometriosis “just” monster cramps?

Endometriosis is not “just” monster cramps. Severe cramping during the menstrual flow is, in fact, more commonly associated with another gynecological condition called adenomyosis. Adenomyosis is where endometriotic tissue is found inside the muscular walls of the uterus and can cause severe cramping and heavy menstrual bleeding. Adenomyosis often co-occurs with endometriosis and for this reason the symptoms of the two conditions are frequently confused with one another.

Endometriosis does not, however, cause uterine cramps nor abnormal bleeding; these symptoms point to a problem with the uterus whereas endometriosis affects tissue outside the uterus.

What is the impact of these symptoms on a woman’s life?

The symptoms of endometriosis can be truly devastating. They can impact upon all areas of a woman’s life rendering her unable to function.

Teenagers with endometriosis may find that they are forced to miss one or more days of school each month while those in employment may find they are struggling to hold down a job due to the need to take leave on a regular basis for severe pelvic pain. Non-prescription pain medications may fail to alleviate the pain and prescription pain medications may only offer partial relief. Maintaining a sexual relationship may be difficult if not impossible due to severe pain during sex. Pelvic pain may interfere with social events and plans and may prevent a woman from partaking in physical exercise. Understandably, over time the symptoms of endometriosis can lead to social isolation, financial difficulties, relationship breakdown and severe emotional distress. Clearly, it is a disease that needs to be taken very seriously and treated effectively as soon as possible to restore a woman’s quality of life.

If you think you may be suffering from endometriosis, don’t suffer in silence. Take your symptoms seriously by talking to your doctor.

Endometriosis excision surgery is currently the only proven treatment that reliably and effectively eradicates the disease.

Key facts summarized

  • Endometriosis excision surgery is currently the only proven treatment that reliably and effectively eradicates the disease. In the vast majority of patients, excision is a curative procedure i.e. after the procedure the disease is eradicated and does not recur. Women who undergo complete excision of their endometriosis can remain disease free for the rest of their lives.
  • No miracle pill, diet or hormone therapy exists that cures endometriosis. Hormones, dietary adjustments, supplements, and herbal remedies can at best result in a reduction in symptoms. They do not resolve the disease itself and if the therapy is discontinued the symptoms will typically return in full force in a short period of time. Non-invasive treatments are at best palliative – they help manage the symptoms of the disease but do not cure the disease.
  • Endometriosis excision surgery will treat the lesions of endometriosis and the pain associated with these lesions. It does not, however, treat other conditions that may co-occur or even result from endometriosis. Symptoms arising from these related conditions may persist despite excision surgery and may require additional treatments in order to restore a patient back to optimal health. For some of these conditions, continued care may be required.

“Endometriosis” and “cure” are rarely seen together in the same sentence. After all, endometriosis is supposed to be a chronic recurrent disease that always comes back, and for many patients, this mantra is borne out in their personal experience with the disease; they undergo repeated failed surgeries and hormone therapies without relief or at best any relief is short-lived and the same old symptoms recur within time.

To confuse matters, endometriosis and pelvic pain are often treated as being synonymous. If the pain returns following previous treatment the patient and her doctor may inadvertently assume that this is an indication of the return of the disease. Pelvic pain, however, is frequently multifactorial in nature, which means the return or persistence of pelvic pain symptoms may not necessarily point to recurrence of previously diagnosed endometriosis. Endometriosis may end up being blamed for other related gynecological conditions that often co-exist with it, such as adenomyosis, pelvic floor dysfunction, adhesion-related pain and interstitial cystitis (painful bladder syndrome).

So, as you can see, the question as to whether or not endometriosis has a cure is far from straightforward!

What do we even mean by “cure”?

In order to answer the question as to whether endometriosis has a cure, it is first necessary to provide the medical definitions of endometriosis and cure.

The medical definition of endometriosis is the presence of ectopic endometrial glands and stroma (said simply, it is the presence of endometrial-like tissue outside the uterus). This definition refers to the actual physical presence of endometriotic lesions but says nothing about the pattern of associated conditions that often co-occur with endometriosis nor of the potential further-reaching effects of the disease on other body systems, such as the gastrointestinal, immune and nervous systems. The medical definition of cure is the absence of a disease following treatment.

So, when talking of cure of endometriosis, according to these medical definitions we are in fact asking whether the endometriotic lesions can be fully eradicated without disease recurrence further along the line. As can be derived from our surgical success rates, recurrence following wide excision by a surgical specialist is uncommon. The vast majority of patients do not experience recurrence of their disease following surgery. These findings are supported by clinical data involving hundreds of patients and are in line with other surgeons around the world who are using the same technique with a similar level of skill. Essentially, endometriosis excision is a highly effective and curative procedure in most cases.

What about disease recurrence despite excision?

In a minority of patients, the disease does recur. Most cases of recurrence are not in fact true recurrence but are in fact disease persistence. It is far more common for an area of disease to be missed or only partially removed than for new disease to occur and most cases of “recurrent” endometriosis after surgery are examples of disease persistence due to incomplete removal of the disease. In such cases, thorough excision of all remaining disease will provide ongoing resolution of the disease. The problem of incomplete surgery lies at the heart of the belief that endometriosis is an incurable disease that always comes back. This is why patients who find themselves on a seemingly never-ending carousel of repeated surgeries should start questioning how complete their surgery has been and whether their surgeon is sufficiently skilled to offer them optimal surgical care.

In rare cases, however, the disease may recur despite thorough excision surgery. Clinical observations made during second look procedures reveal that recurrence following excision surgery tends to occur at the margins of previous areas of excision. It is far less common for the disease to recur in new sites. Furthermore, recurrent disease tends to be more limited in presentation than the original manifestation of the disease (women with recurrent disease typically have less disease than at the time of their first surgery and recurrent disease is superficial). One possible explanation for the patterning of recurrence at the margins of previously excised areas is that the healing process itself may trigger vulnerable tracts of tissue that contain a latent potential to become endometriosis to then transform into new areas of subtle disease in some patients. Performing excision with wide margins around the areas of visible disease can help reduce the risk of recurrence.

The youngest patients may be at greater risk of disease recurrence although the data are mixed. A recent study found no recurrence in a small series of teenage patients following broad excision. Younger patients may present with more subtle presentations of the disease that are easier to overlook or areas of healthy appearing tissue may still harbor a latent potential to subsequently transform into endometriosis through a process of metaplasia (where one tissue type transforms into another tissue type). It is therefore important to treat endometriosis in teenagers with broad excision to minimize the risk of the patient later having to return for further surgery. Even in teenagers, most patients will experience complete and ongoing resolution of their disease following a single surgical excision procedure.

The sites in the body most likely to undergo “recurrence” following surgery are in fact the ovaries. In the case of ovarian disease deep within the ovarian tissue, it may be difficult if not impossible to detect small focal areas of disease during surgery. Ovarian endometriomas can be excised but sometimes a patient will have other small areas of disease within the ovary that are only detected if they later develop into new endometriomas. The rate of recurrence following excision of an endometrioma (cystectomy) is estimated to be around 5%. Obviously, the risk of recurrence varies depending on the skill of the surgeon.

Recurrence of deep disease is extremely rare. If an area of deep endometriosis is found following previous surgery it is highly likely that the initial surgery failed to completely remove the lesion.

Will removal of my endometriosis cure me of all my symptoms?

This is an important question. The lesions present in the pelvis may only represent half of the picture. Is endometriosis “just” about the lesions or is it more complex than that? The disease process itself (chronic pelvic pain and inflammation) and the underlying factors that determine which women ultimately develop the disease may also result in wider system dysfunction that persists even after the lesions themselves have been meticulously removed. In many cases, endometriosis may present as a multi-systemic “syndrome” of deficits extending far beyond the pelvic cavity. A comprehensive integrative approach may be required in order to restore optimal health. In short, surgery can remove the lesions but other treatments and therapies may be required to address other symptoms indirectly associated with endometriosis.

What does it mean to be “fighting for a cure”?

If endometriosis can be effectively surgically removed with little risk of recurrence, why are endometriosis advocates fighting for a cure? While surgical treatment offers curative resolution of the disease there is currently no way of preventing the development of the disease in the first place and many women experience a long and painful diagnostic delay and rounds of ineffective treatment before accessing optimal care. There is no non-invasive diagnostic test for endometriosis nor a non-invasive curative treatment. What we really should be fighting for is improved access to care, new treatment options, earlier diagnosis, and ultimately a way of stopping the disease in its tracks before it has a chance to debilitate lives. We should be fighting for a prevention.

Many women with endometriosis who suffer from pelvic pain will also have co-existing urogynecological disorders that contribute to their symptoms. Sometimes one disorder may mask other co-occurring disorders and it takes a skilled physician to correctly differentiate the many possible sources of pelvic pain.

While endometriosis is a leading cause of pelvic pain, pelvic pain is often multifactorial in origin – it can stem from multiple causes.

The following conditions commonly co-occur with endometriosis and represent additional causes of pelvic pain:


Adhesions are bands of fibrotic tissue (scar tissue) that form between adjacent organs and structures, such as between the ovaries and pelvic sidewall and between the uterus and bowel. Adhesions can be thin, cobweb-like or dense and thick like hardened glue. They arise from pelvic disease, infection or injury. Over time the inflammation associated with endometriosis can cause the formation of scarring and adhesions and the surgery to remove the disease may result in further adhesions as the body heals. Some patients are more prone to forming adhesions than others. In severe cases it is almost as if a tube of superglue has been deposited into the pelvic cavity, causing structures to fuse and distorting the pelvic anatomy. If adhesions stretch or constrict a vital structure such as the bowel this can result in pain and other symptoms, such as bowel obstruction and nausea. Surgery can be performed to remove painful adhesions. A problem, however, is in preventing the adhesions from reforming during the healing process. The use of adhesion barriers and an early second look procedure to take down newly forming adhesions before they become established can help provide ongoing relief.


Adenomyosis is a close relative of endometriosis, and is when endometriotic tissue is found within the muscular walls of the uterus. The two main symptoms of adenomyosis are severe uterine cramping that worsens with the menstrual flow and unusually heavy periods. Not all women with adenomyosis have symptoms.

Interstitial cystitis (painful bladder syndrome)

Interstitial cystitis (IC) is a chronic bladder condition that often mimics a bladder infection. The most common symptoms are pelvic pain, pelvic pressure, pain with urination, urinary frequency and urinary urgency. Women with IC typically have smaller bladder capacity and when the inside of the bladder is inspected via cystoscopy glomerulations (small capillary bleeding from the bladder wall) and Hunner’s ulcers (lesions or sores on the lining of the bladder) may be observed. Unlike endometriosis, IC cannot be surgically removed but there are treatments that can help manage symptoms, including dietary changes, bladder instillations and medications.

Pelvic floor muscle spasm

Chronic pelvic pain can result in a tightening of the pelvic floor muscles. When the pelvic floor muscles become overly tight or overly relaxed or loose (such as following childbirth) the patient is said to have Pelvic Floor Dysfunction (PFD). Some patients with endometriosis or other forms of chronic pelvic pain will go on to develop pelvic floor muscle spasms due to a tightening of the pelvic floor muscles in response to ongoing severe pelvic pain. Pelvic floor muscle spasms are excruciatingly painful and can occur spontaneously or become triggered by activity, such as sexual intercourse. Pelvic physical therapy can help alleviate the painful and debilitating symptoms of PFD and pelvic floor muscle spasm.


Fibroid tumors are accumulations of smooth muscle tissue that form within the muscular walls of the uterus. A woman may develop multiple fibroids and the tumors can vary in size from smaller than a marble to larger than a grapefruit. Fibroids if symptomatic can cause heavy periods and uterine cramping that worsens with menstruation.

Uterine retroversion

Normally the uterus is anteverted; it is tilted forward slightly, toward the bladder. In approximately 1 in 5 women the uterus is retroverted; it is tilted backward toward the bowel. While retroversion of the uterus is considered a normal phenomenon it can be associated with lower back pain, painful sex and painful bowel movements. Retroversion may be more symptomatic in women who have co-occurring uterine pathology, such as fibroids and adenomyosis.

Uterine prolapse

Uterine prolapse is when the uterus drops down into and sometimes out of the vagina. It is more common in patients who have had previous vaginal deliveries, as the process of childbirth can loosen the pelvic support structures that support the uterus. Prolapse is also more common in women post-menopause as the drop in estrogen levels can also reduce the tone of the support structures in the pelvis. Patients suffering from prolapse may complain of a bearing down sensation and lower back pain. Prolapse may also be associated with stress incontinence (where lifting, coughing, sneezing and/or exercise result in loss of urine).

Pelvic congestion

Pelvic congestion, uterine varicosities and ovarian vein varicosities (varicose veins) are all variations of enlarged pelvic blood vessels and may present as a source of pelvic pain. Pelvic congestion may be manageable conservatively or via radical organ removal (hysterectomy) depending on the site of the varicosities.

Ovarian cysts

The most common non-endometriotic ovarian cysts are functional cysts (follicular cysts and corpus luteal cysts). Functional cysts form and resolve as a normal part of the menstrual cycle. Sometimes functional cysts may persist longer than normal and cause pain. Even the presence of one or more small to medium-sized cysts can stretch the ovary causing pain. If the ovary is also involved by scar tissue or adhesions, the presence of a functional cyst during the cycle can cause a cyclical stretching of the scar tissue producing a painful pulling sensation. If a cyst ruptures, this may result in acute pain. Not all cysts are symptomatic. Sometimes a patient will have large ovarian cysts without any symptoms at all. Non-functional cysts include endometriomas, hemorrhagic corpus lutea and dermoid cysts. Imaging can help differentiate between functional and non-functional cysts. Endometriomas and dermoid cysts do not resolve on their own without surgery.

Ovarian torsion

Ovarian torsion is when an ovary twists on itself. Torsion is associated with acute lower abdominal pain and represents a medical emergency. If the torsion is not resolved quickly the blood supply to the ovary may be compromised and the ovary may cease to function, resulting in loss of the ovary.

Abdominal wall neuropathy

The ilio-inguinal, ilio-hypogastric, and genital femoral nerves are found in the lower abdominal wall between the belly button and hipbone, down to the groin and upper leg. When these nerves are damaged, a nerve block or trigger-point injection can be helpful; often, a series of nerve blocks can ease the pain. In some cases, a technique called radiofrequency nerve ablation is used to provide longer lasting relief.

Pudendal neuropathy and pudendal nerve entrapment (PNE)

The pudendal nerve is located along the side of the vagina. This nerve has three basic branches: an anterior branch, to the clitoris; a middle branch, to the vaginal and vulvar area; and a posterior branch, to the anus. Pain can be present in any portion of the nerve if it becomes damaged or entrapped. The pain is often worse when the patient is sitting. Pudendal neuropathy can be treated with pudendal nerve blocks and pelvic physical therapy. In some cases radiofrequency ablation of the pudendal nerve may be helpful.

Ovarian remnant syndrome

An ovarian remnant is when a small piece of ovarian tissue is left behind following removal of an ovary. This can occur if the ovary is fused by adhesions to the adjacent pelvic sidewall prior to removal. In such cases, the ovary must first be carefully peeled away from the adherent structures without leaving a remnant behind. Ovarian remnant syndrome is when a patient experiences pain as a result of the ovarian remnant. Sometimes a remnant will be identified by the presence of a cyst in the ovarian tissue on ultrasound or by persistently elevated estrogen levels (in the case of removal of both ovaries). Ovarian remnant syndrome can be resolved by surgically removing the remaining remnant of ovarian tissue.

Foreign body

Pelvic pain may result from foreign materials left in the body after a previous procedure, such as surgical staples and mesh. Sometimes a foreign body may result in a chronic inflammatory reaction called a foreign body giant cell reaction. Foreign body reactions can be resolved by removing the source of the reaction. Avoiding the use of foreign non-biodegradable materials in the body can prevent these reactions from occurring in the first place.


Groin hernias include inguinal, obturator and femoral hernias. Inguinal hernias are the most common. Inguinal hernias are actually an uncommon source of pelvic pain and are often over-diagnosed and treated with mesh, which can then become a new source of pelvic pain. For this reason, inguinal hernias should be treated without mesh. Sometimes a patient may develop a painful abdominal wall hernia, including umbilical hernias, incisional hernia and ventral hernias. Surgical correction can resolve the hernia and any associated pain.


Appendicitis is a condition in which the appendix becomes inflamed. In the case of acute appendicitis, the onset of inflammation is sudden and is accompanied by severe right-sided pelvic pain that brings the patient to the ER and the appendix is removed during emergency surgery. Occasionally a patient will present with chronic appendicitis or her acute pain will be passed off as endometriosis pain, potentially leading to a life-threatening situation if the appendix then ruptures.

Food sensitivities and food allergies

While technically different, food allergies and food sensitivities can result in similar types of problems. A food allergy, such as to seafood, is mediated by the immune system: the patient may break out in a rash and/or may experience difficulty breathing. A food sensitivity, such as lactose intolerance, has an end-organ response: the patient reacts to the food with, for example, a spasm of the bowel.

Gluten is a protein found in wheat, rye, barley, oat bran, and wheat germ. While it can cause celiac disease, gluten is also a leading cause of food sensitivity. The symptoms are very similar. With celiac disease, the lining of the gastrointestinal tract becomes damaged, but the pain with gluten sensitivity – such as severe bowel pain, up to a level of 10/10 – can be just as severe. Other symptoms include bloating, diarrhea, skin problems, headaches, even neurologic symptoms, such as irritation and anxiety. Food sensitivities can also contribute to or cause pain in the vulvar area and make interstitial cystitis symptoms worse.

Gastrointestinal problems

Bowel problems are common in pelvic pain patients. Many patients report bloating, cramping, gassiness, and alternating bouts of constipation and diarrhea. One cause of gastrointestinal problems includes food allergies and sensitivities. Other causes of gastric symptoms include bowel motility problems or spastic bowel, bowel obstructions due to adhesions, redundant colon (an extra length of colon), diverticulitis (when a small pouch forms in the colon and becomes infected) and anal fissures, a crack in the lining of the anus, often resulting from constipation.

Generalized visceral hypersensitivity

Visceral refers to the internal organs and hypersensitivity refers to abnormally increased sensitivity. With generalized visceral hypersensitivity, the entire inside of the body hurts. This is usually because inappropriate signals are being sent by the nervous system, creating types of neuropathic pain or centralized pain.


The vulva is the area surrounding the outside of the vagina. Vulvodynia means “pain of the vulva.” There are two general types of vulvodynia. Patients with generalized vulvodynia can experience pain anywhere on the vulva between the thighs. It can involve the entire area or specific, isolated areas. The pain can be intermittent or constant. Vulvar vestibulitis involves pain of the vestibule, the small area around the opening of the vagina inside the labia minora, or inner lips. Pain is only present with pressure on the area, such as with intercourse or tampon insertion.


Ready to start your healing journey? Request a free virtual consultation today.


At this point in time, we do not know the cause of endometriosis. When considering the origin and manifestation of a disease we need to consider the factors that determine whether a woman develops the condition or not and, of those women who do develop the disease, the factors that determine how severe her disease ultimately is (how symptomatic, how aggressive, how invasive and how extensive).

Until now several theories of the origin and disease manifestation of endometriosis have been proposed. The aim of a theory of origin is to present an explanation that adequately accommodates all that we know about the disease. Generally, the best-fit theory is adopted and used to guide and predict treatments and outcomes. Over time if new information becomes available the best-fit theory may be surpassed or replaced by another competing theory or alternatively may be adapted in order to accommodate the new findings.

Sampson’s theory of retrograde menstruation

Perhaps one of the most popular and enduring theories of origin is that of retrograde menstruation, transportation, and implantation. This is the belief that endometriosis occurs through a process of endometrial tissue flowing back through the fallopian tubes during menstruation, entering the pelvic cavity and implanting and invading the surfaces of the pelvic structures.

Retrograde menstruation, however, is a common phenomenon that occurs in 90% of women yet only 10% of women develop endometriosis and the refluxed material only contains minimal deposits of endometrial tissue. Furthermore, endometriosis consists of tissue that is similar but not identical to the native endometrium that lines the uterus, suggesting that it is not a mere autotransplant. Other phenomena about the disease that cannot be adequately explained by this theory include the presence of endometriosis in stillborn female fetuses, in women without a functional uterus and in a small number of men undergoing treatment for prostate cancer. The theory of retrograde menstruation predicts that the disease will recur after surgery and worsen over time with each menstrual flow, yet surgical excision of endometriosis has been found to effectively remove the disease in most patients with true disease recurrence being rare. Studies examining the extent of disease across different age groups of patients have failed to find an increase in disease with age.

Immune dysfunction theory

Research reveals that women with endometriosis are at increased risk of also having various autoimmune disorders, including allergies, systemic lupus erythematosus, Sjögren’s Syndrome, rheumatoid arthritis, and multiple sclerosis. Based on this finding a hybrid theory was developed that extends upon Sampson’s theory of retrograde menstruation. As mentioned above, retrograde menstruation occurs in around 90% of women yet only a minority ever develop endometriosis. It has been hypothesized that an underlying immune dysfunction interferes with the body’s natural ability to clear up this refluxed tissue from the pelvis and therefore the tissue is allowed to establish itself and proliferate, resulting in endometriosis. This line of argument suffers many of the same limitations as the original theory of retrograde menstruation. While autoimmune disorders are more common in women with endometriosis, many women with endometriosis do not have any such disorders. Another important question is whether immune dysfunction truly precedes the onset of endometriosis or rather is it a result of the disease process itself. Endometriosis triggers an ongoing immune response, which over time could moderate or disrupt immune function, altering an individual’s propensity to developing autoimmune disorders.

Theory of Mülleriosis

The theory of Mülleriosis is the notion that endometriosis is already laid down during embryonic development and remains dormant until later in life when changes in hormones (such as during puberty or pregnancy) trigger the disease to become active and symptomatic. During embryonic development, tissue is laid down and differentiated into the various pelvic organs and structures that form the pelvis, including the reproductive organs. In women with endometriosis, something goes awry during this process and tissue that would ordinarily be restricted to the inside of the uterus ends up developing in locations outside the uterus. A helpful analogy is that of a chef who is following a recipe for a full course dinner. He has all of the right ingredients but the recipe contains mistakes and some of the ingredients that should belong in the starter end up in the desert and some ingredients intended for the dessert end up in the main course. In the development of the reproductive organs, HOX genes determine which tissue develops where. It is possible that abnormalities in these genes, whether spontaneous or inherited, result in coding errors that in turn result in the presence of aberrant endometriotic tissue outside the uterus (endometriosis). This theory can explain why the disease has been observed in infants and prepubescent girls, as well as the presence of other types of aberrant tissue that may co-occur with endometriosis, such as endocervicosis (tissue similar to the cervix found outside the uterus) and endosalpingiosis (tissue similar to the lining of the fallopian tubes present outside the tubes). It could also help explain the unique patterning of the disease i.e. why it occurs more commonly in some locations than others. Interestingly, there is a pattern of abnormalities and anomalies, such as urinary tract and uterine anomalies, adenomyosis, fibroids, and peritoneal pockets that are significantly more common in patients with endometriosis. This syndrome of conditions could be explained by a common underlying pattern of “coding errors” that manifest during embryonic development.

Embryonic rest theory

The embryonic rest theory proposes that cells of Müllerian origin can persist within the peritoneal cavity and under certain circumstances induce the formation of endometriotic tissue. An embryonic rest is a remnant of embryonic tissue that has persisted beyond the embryonic phase of development. Cells of Müllerian origin are the embryonic cells that originally comprised the Müllerian duct, a structure that subsequently differentiated into the female reproductive organs (specifically the fallopian tubes, the uterus and part of the vagina). It is unknown, however, whether these cells really can persist beyond early life.

Stem cell theory

A recent theory is that endometriosis arises from endometrial stem cells located outside the uterus. Stem cells are undifferentiated cells that harbor the potential to regenerate and produce more differentiated “daughter” cells. It is proposed that stem cells located in the pelvis outside the uterus bring about the regeneration and differentiation of endometriotic lesions. These same cells play a role in the monthly regeneration of endometrial tissue inside the uterus after each menstrual flow.

Theories of lymphatic and vascular spread

In very rare cases a patient will present with endometriosis in far away places, such as the lung, the brain or even the eye. One explanation for these occurrences is that small amounts of endometrial tissue can spread throughout the body via the lymphatic and vascular system. It is unclear, however, how this process would occur and perhaps a more plausible explanation is that the disease presents in these distant sites due to a process of coelomic metaplasia (the transformation of cells or tissue from one type to another).

Coelomic metaplasia theory

Coelomic metaplasia rests on the notion that any cell in the body has the potential to become any other cell. All cells have the same basic genetic code but are differentiated by the different ways in which their basic genetic code is expressed. The expression of any given cell’s genetic code may be influenced by any manner of factors (such as inflammation, exposure to toxins, and wound healing). In the case of endometriosis, the theory of coelomic metaplasia predicts that the genetic material in a cell or a group of cells (tissue) becomes expressed differently causing the tissue to transform into endometriosis. This theory could explain the occurrence of disease in distant sites in the body, scar endometriosis, and the presence of disease in men undergoing treatment for prostate cancer.

Genetic factors

It has been found that endometriosis runs in families. A woman’s risk of developing the disease is significantly increased if her mother or sister also has the disease. These findings point to a genetic origin of the disease. What we do know is that no individual gene is responsible for endometriosis and the pattern of inheritance is complex. Most likely a complex array of genes are involved in the familial transmission and expression of this disease and these genes may interact with environmental factors to determine disease extent and severity.

Environmental toxins

With an increase in exposure to toxins in the surrounding environment (air pollutants, toxic chemicals in household products and in the food chain) as well as increasing exposure to estrogens in the foods we consume it has been hypothesized that more women may develop endometriosis than previously or that the severity of endometriosis may be exacerbated by exposure to certain chemicals. There are two potential mechanisms through which environmental factors may play a role. Firstly there is the potential for dioxin exposure in vitro to result in genetic mutation, which in turn could cause the disease to occur, and secondly, exposure to certain chemicals over the lifespan could enhance disease activity or even result in an underlying “latent” susceptibility to the disease becoming expressed. If an area of tissue harbors the potential to become endometriosis through metaplasia, an environmental factor could be the catalyst that triggers this change to occur. This brings up the role of epigenetics, which is when external factors alter the expression of a person’s genes. Alterations in gene expression can, in turn, result in changes in the behavior of cells in the body. It is important to note, however, that endometriosis has existed for millennia.

As you can see, various theories have been proposed to explain the origin and presentation of endometriosis. The question of what causes this disease and why some women present with more advanced and aggressive disease than others is far from simple. At this point in time, we do not have all the answers. Most likely a complex interplay between several of the above-described theories ultimately holds the key to fully unraveling the cause and in turn the cure of this enigmatic disease.

Copyright © 1996-2018 Vital Health Endometriosis Center. All rights reserved. Web Design by WorldLight Media