Colon Chronicles: Delving into Bowel Endometriosis

Colon Chronicles: Delving into Bowel Endometriosis

In our recent blog, we highlighted the significance of addressing bowel endometriosis, a condition prone to misdiagnosis. Whether individuals have struggled with lifelong bowel issues or are suddenly facing disruptions, determining what’s considered normal can be perplexing. The “normal” range spans anywhere from three times a day to as infrequent as three times per week. In many sources, the focus is typically limited to frequency and to some degree consistency; however, there’s an overall scarcity of information on what defines normalcy. 

ICYMI: Understanding Bowel Endometriosis

This ambiguity is particularly challenging for those with endometriosis, where gastrointestinal symptoms vary widely, making it tough to discern what’s amiss. About 90% of endometriosis cases involve some form of gastrointestinal symptoms, often leading to an IBS (irritable bowel syndrome) diagnosis, which essentially offers a label for persistent symptoms without an identifiable cause. The usual next step in diagnostics is often a colonoscopy, a key tool for identifying or ruling out certain diseases. This article explores the nuances of bowel endometriosis, with a primary focus on the role and precision of colonoscopy in diagnosing this condition.

Bowel endometriosis is considered to be deep infiltrating endometriosis and can lead to a variety of symptoms which we discussed in the previous blog, but is often concerning if not diagnosed timely and may risk more complex surgeries including resection if the disease is not properly addressed. 

Related Reading: How to Get an Endometriosis Diagnosis

The Role of Colonoscopy – Is it helpful?

A colonoscopy is a diagnostic procedure commonly used to examine the inner lining of the large intestine (colon and rectum). It involves the use of a long, flexible tube called a colonoscope, which has a small camera attached to its end. This tool allows physicians to visualize the interior of the colon to identify any abnormal conditions or changes.

In the context of bowel endometriosis, a colonoscopy can potentially detect signs of endometrial tissue growth within the bowel. However, its effectiveness and accuracy in diagnosing this condition have been subjects of ongoing research and debate. Aside from its ability to detect endometriosis, there is also consideration of the provider performing the procedure and their level of knowledge of endometriosis. 

The use of colonoscopy in diagnosing bowel endometriosis has been a topic of considerable discussion among medical professionals. Given the invasive nature of the procedure and the often non-specific symptoms of bowel endometriosis, the role and necessity of colonoscopy in its diagnostic process have been questioned.

However, several case studies and research findings suggest that colonoscopy can indeed play a crucial role in identifying bowel endometriosis. In particular, it has been found to be effective in detecting endometriosis growth in the bowel, with certain colonoscopic findings such as eccentric wall thickening, polypoid lesions, and surface nodularities often being associated with endometriosis.

Evaluating the Accuracy of Colonoscopy for Diagnosing Bowel Endometriosis

While the potential of colonoscopy in detecting bowel endometriosis has been recognized, its accuracy in doing so has been the subject of extensive research. A number of studies have sought to evaluate the sensitivity, specificity, and predictive values of colonoscopy in diagnosing this condition.

One such study was conducted by Milone M et al., who performed a prospective observational study that included women diagnosed with deep pelvic endometriosis. The study aimed to evaluate the accuracy of colonoscopy in predicting intestinal involvement in deep pelvic endometriosis.

The results of the study suggested that colonoscopy did have the potential to detect bowel endometriosis, with a number of cases accurately diagnosed through the procedure. However, the overall sensitivity, specificity, and predictive values of colonoscopy were found to be variable, indicating room for improvement in its diagnostic accuracy.

In another study conducted by Marco Milone and his team, the researchers also found that while colonoscopy could indeed identify bowel endometriosis, its accuracy was not optimal. The study elucidated that the presence of colonoscopic findings of intestinal endometriosis in deep pelvic endometriosis was quite low, indicating that routine colonoscopy may not be justified for all women with deep pelvic endometriosis.

A Case Study: Bowel Endometriosis and Colonoscopy

To illustrate the potential role of colonoscopy in diagnosing bowel endometriosis, let’s consider a case study involving a 45-year-old woman who presented with abdominal pain in her left lower quadrant. This woman underwent a colonoscopy, which revealed a submucosal tumor-like lesion in her sigmoid colon.

Upon further examination using magnifying endoscopy, the lesion was found to contain sparsely distributed round pits – a finding that was suggestive of endometrial glands and stroma (the histological definition of endometriosis). This discovery led to a biopsy of the lesion, the results of which confirmed the presence of intestinal endometriosis.

This case study serves to highlight how colonoscopy, when combined with other diagnostic methods like magnifying endoscopy and biopsy, can aid in the detection and diagnosis of bowel endometriosis.

The Future of Bowel Endometriosis Diagnosis

While the role and accuracy of colonoscopy in diagnosing bowel endometriosis have been explored, research in this area is ongoing. The development and refinement of diagnostic methods are crucial for improving the detection and treatment of bowel endometriosis.

In parallel with the innovations in medical technology, new diagnostic methods such as magnifying chromoendoscopy, target biopsy, and virtual colonoscopy are being explored and studied for their potential to improve the accuracy of bowel endometriosis diagnosis. These advancements, coupled with a deeper understanding of the condition, may pave the way for more accurate and less invasive diagnostic options in the future.

Bowel endometriosis is a complex condition that can significantly impact the quality of life of those affected. While colonoscopy can play a role in its diagnosis, its effectiveness and accuracy are subject to continuous research and improvement. Exploring new diagnostic methods and refining existing ones are crucial steps toward enhancing the detection and treatment of this condition. As we continue to learn more about bowel endometriosis and its nuances, we can hope for more efficient and accurate diagnostic tools in the future.

Related Reading:

  1. Endo-Fighting Microbiome Optimization: Research-based Tips
  2. Endometriosis and the Microbiome: Insights and Emerging Research


  1. Walter SA, Kjellström L, Nyhlin H, Talley NJ, Agréus L. Assessment of normal bowel habits in the general adult population: the Popcol study. Scand J Gastroenterol. 2010;45(5):556-566. doi:10.3109/00365520903551332
  2. Habib, N., Centini, G., Lazzeri, L., Amoruso, N., El Khoury, L., Zupi, E., & Afors, K. (2020). Bowel Endometriosis: Current Perspectives on Diagnosis and Treatment. Int J Womens Health, 12, 35-47. 
  3. Milone, M., Mollo, A., Musella, M., Maietta, P., Sosa Fernandez, L. M., Shatalova, O., Conforti, A., Barone, G., De Placido, G., & Milone, F. (2015). Role of colonoscopy in the diagnostic work-up of bowel endometriosis. World J Gastroenterol, 21(16), 4997-5001. 
  4. Tomiguchi, J., Miyamoto, H., Ozono, K., Gushima, R., Shono, T., Naoe, H., Tanaka, M., Baba, H., Katabuchi, H., & Sasaki, Y. (2017). Preoperative Diagnosis of Intestinal Endometriosis by Magnifying Colonoscopy and Target Biopsy. Case Rep Gastroenterol, 11(2), 494-499. 

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