Bowel Endometriosis Treatment in Newport Beach, CA

What is Bowel Endometriosis

Bowel endometriosis is a form of endometriosis where tissue similar to the uterine lining grows on the intestines or other structures within the abdomen. This endometrial-like tissue acts similar to the uterine lining, bleeding and causing inflammation that worsens cyclically with menstruation. Unlike menstrual blood from the uterus, which exits the body, the bleeding from bowel endometriosis occurs within the abdominal cavity or into the bowel itself. Small amounts of blood are broken down and absorbed by the body and a major source of the inflammation and irritation that causes pain and bowel dysfunction. Bowel endometriosis can lead to serious complications like bowel obstruction if left untreated and also often impacts fertility.Determining the exact prevalence of bowel endometriosis in the U.S. is challenging, but it’s estimated that around 3 – 37% of women with endometriosis have bowel involvement. This wide range reflects the variation in how studies define and diagnose bowel endometriosis.  Many cases likely go undiagnosed due to how it mimics other digestive conditions and has far less awareness as compared to endometriosis affecting the pelvic organs.  Many women with bowel endometriosis have their symptoms dismissed as IBS (Irritable Bowel Syndrome)  or other bowel disorders, leading to underdiagnosis.

The Location of Endometriosis Within the Bowel 

Research has determined 90% of bowel endometriosis cases involve the large intestine (colon), especially the sigmoid colon (the S-shaped final portion of the colon, before the rectum) and rectum (the very last section of the large intestine).  Less frequently but it can also involve the small intestine, particularly the last portion (ileum) closest to the large intestine, appendix, and surrounding areas.  Some women have lesions scattered throughout sections of the small intestine. Endometriosis can grow on the external surface of the bowel, infiltrate deeply into the muscular layers of the intestine itself, or invade adjacent structures like ligaments supporting the bowels.  In very rare cases, endometriosis can even be found in the upper digestive tract (stomach, esophagus) or respiratory system.  

The specific location of bowel endometriosis matters because it influences the type of pain and digestive problems experienced. For example, rectal-associated endometriosis tends to cause pain during bowel movements and potential bleeding.   Also, where the bowel endometriosis is located helps determine which imaging tests (ultrasounds, MRI) or procedures (colonoscopy) are most useful for diagnosis.  Lastly, endometriosis lesions in certain areas of the bowel may require more complex surgical techniques and a team approach involving a colorectal surgeon.

Complications of Bowel Endometriosis

While treatable, bowel endometriosis can lead to a range of complications, some potentially quite serious. Bowel endometriosis inflicts its damage and causes a wide range of disruptive symptoms.  Similar to endometrial tissue inside the uterus, endometriosis implants on the bowels respond to hormonal changes and bleed during menstruation creating intense inflammation.  That inflammation in turn irritates the bowel wall and the network of nerves traversing the intestines, producing many of the painful symptoms.  Abdominal pain is the hallmark of bowel endometriosis, often cyclical and worsening around menstruation, and can range from light cramping to sharp debilitating pain.

Endometriosis lesions often deeply infiltrate the bowel wall growing inward into the muscle layers. This can distort the normal structure and disrupt how the bowels contract to move stool. The body’s attempts to self-heal can lead to intestinal fibrosis (an excessive accumulation of scar tissue in the intestinal wall)  which can create stiffness and further disrupt the bowel’s normal functions. The disrupted bowel movements can cause stool to either move too slowly (constipation) or too quickly (diarrhea), sometimes alternating between the two. Impaired movement of gas and stool contributes to bloating and a feeling of uncomfortable abdominal fullness. Especially likely to occur during menstruation, as the inflamed lesions bleed within the bowel. In severe cases, bowel dysfunction can trigger nausea and vomiting.

Very serious complications can arise from bowel endometriosis and lead to the development of fistulas or abnormal connections between two organs or structures.  The chronic inflammation caused by endometriosis can weaken and break down the bowel wall and surrounding tissues creating an ulcer-like defect.  This can happen with the:

• Bladder: Fistula forms between the bowel and bladder.
• Vagina: Fistula forms between the bowel and vagina.

As a result bowel contents (gas or stool) can pass through the fistula and into the connected organ increasing the risk of recurrent infections, pain, unusual discharge, urinary changes, and more. Also and while less common, endometriosis can cause narrowing of a bowel segment or total blockage. This prevents stool from passing and is a medical emergency.

Symptoms of Bowel Endometriosis

It’s important to remember that there’s no single “typical” presentation of bowel endometriosis and symptoms can vary significantly in their intensity and combination.  Primary symptoms are  deep pelvic pain, pain during sex, and painful bowel movements accompanied by sharp cramping or a feeling of intense pressure. The pain can be debilitating and surge with menstruation.   Some women have a feeling of uncomfortable fullness, pressure or bloat in the abdomen, even when not needing to experience a bowel movement.  Bowel movements themselves can become irregular and accompanied by constipation (difficulty passing stool), diarrhea (loose and frequent stools) or an alternating pattern of both.  Rectal bleeding is possible, particularly with menstruation and can range from bright red spotting to darker blood mixed within the stool.  In more severe bowel endometriosis cases, an upset digestive system can lead to nausea and even vomiting.

Because bowel endometriosis symptoms closely mimic digestive or gastrointestinal pain, to where even professional physicians often mistaken it for irritable bowel syndrome (IBS). The difference between bowel endometriosis and IBS is in the frequency and severity of pain.  Women with IBS or other gastrointestinal conditions tend to experience pain multiple times during a week over the course of a month, whereas the intense pain of bowel endometriosis very frequently surges and subsides with the menstrual cycle.

Some women have severe symptoms with minimal endometriosis, while others may have few issues despite extensive disease.  Women experience bowel endometriosis symptoms in a variety of ways including having no symptoms, other than their fertility being affected.  If you experience any of these symptoms, particularly if they follow a cyclical pattern with menstruation, further investigation is sensible and warranted. 

Diagnosis of Bowel Endometriosis

Diagnosing bowel endometriosis requires a multifaceted approach starting with a comprehensive review of your medical history and current symptoms, medications and health conditions.  Initially it’s important to rule out other possible conditions and identify any cyclical patterns of worsening bowel symptoms (pain, constipation, diarrhea, bloating) accompanying menstruation.  A physical exam will involve pain mapping or pinpointing where the pain is located and its specific characteristics (sharp, crampy, etc.) which helps guide further investigation.  I may check  for tenderness or palpable nodules that might provide clues, but can be normal even with bowel endometriosis. 

Transvaginal/Transrectal Ultrasound can detect larger bowel endometriosis lesions, but many cases are missed by standard ultrasounds thus a more specialized MRI of the pelvis may be warranted.  While not foolproof, a specialized MRI of the pelvis with rectal contrast can be a helpful tool in detecting some cases of bowel endometriosis.  In such a scenario a special contrast material (often a gel) is carefully inserted into the rectum. This fills the lower part of the colon, outlining its shape and making the bowel wall easier to evaluate on MRI images.  MRI images are most helpful when deep endometriosis is suspected and can sometimes show the location and approximate size of bowel endometriosis implants, particularly larger ones. It can also provide clues about whether the endometriosis is superficial (on the surface) or deeply infiltrating the bowel wall.  For example, if endometriosis causes narrowing or tethering of the bowel, this may be visible on the MRI.  If symptoms strongly suggest bowel involvement, MRI helps plan a surgical approach, map out the extent of endometriosis in multiple areas of the pelvis alongside the bowel and helps visualize other pelvic problems that might mimic bowel endometriosis symptoms.

However, MRI is a diagnostic tool rather than a definitive answer, can miss smaller lesions or those in certain locations within the bowel and doesn’t replace direct visualization. Biopsy (tissue removal)  during colonoscopy or surgery is often still needed for confirmation of bowel endometriosis.   Colonoscopy allows for direct visual inspection of the inside of the colon and biopsy any suspicious areas.  While primarily a surgical procedure, during a laparoscopy focused on endometriosis excision, direct visualization of bowel involvement is important for diagnosis and treatment as well.  If any suspicious lesions are found during colonoscopy or laparoscopy, taking a tissue sample (biopsy) and having it analyzed by a pathologist is required for confirmation of bowel endometriosis.  

Treatment of Bowel Endometriosis

Treatment of bowel endometriosis typically involves a multifaceted approach to achieve both symptom control and disease removal. Birth control pills, progestin-only options (pills, IUD, injections), or GnRH (Gonadotropin-releasing hormone) can help reduce inflammation but will not cause resolution of the lesions.  While these hormonal medications provide pain relief and may improve bowel function, they usually suppress endometriosis and don’t eliminate it entirely.  Thus medication is commonly used prior to surgery to shrink endometriosis lesions, or after surgery to reduce the risk of recurrence.

Laparoscopic surgical excision is the gold standard for treatment of bowel endometriosis, offering the best chance of long-term improvement of pain and range of bowel endometriosis symptoms. The complexity of surgical excision can vary from simple removal of surface lesions to more extensive procedures involving bowel resection (removing a segment of bowel) followed by reconnection.

Bowel resection is required in cases when: 

• endometriosis grows deeply into the muscular layers of the bowel wall or;
• pain, bowel dysfunction (constipation, obstruction), bleeding are significant and unresponsive to other treatments or;
• complications like bowel fistulas (abnormal connections) or near-complete blockage exist.

More involved surgery often requires a surgical team and carries higher risks of complications than simpler endometriosis excision procedures.  The best treatment plan is tailored to your specific symptoms, the location and severity of your endometriosis, fertility goals, and overall health. Let me know if you’d like a more detailed explanation of the specific surgical techniques used for bowel endometriosis or want to explore options for ongoing bowel symptom management.