Colon polyps are growths on the inner lining of the large intestine. While many polyps cause no symptoms, some can lead to diarrhea, especially larger or specific types. This article clarifies the relationship between colon polyps and changes in bowel habits.
What Are Colon Polyps
Colon polyps are small tissue growths that develop on the inner surface of the colon or rectum. These growths can vary in size and shape, appearing as small bumps, mushroom-like structures on a stalk (pedunculated), or flat lesions (sessile). Most colon polyps are harmless and do not cause symptoms, often discovered during routine screenings.
Polyps form when cells lining the colon begin to grow abnormally, a process often linked to genetic changes. They are broadly categorized into non-neoplastic and neoplastic types. Non-neoplastic polyps, such as hyperplastic polyps, typically do not become cancerous, while neoplastic polyps, primarily adenomas, have the potential to develop into colorectal cancer over time. Adenomas are the most common type and are considered precancerous, making their detection and removal important for cancer prevention.
Common Signs of Colon Polyps
Many colon polyps, especially when small, do not cause noticeable symptoms. This is why screening is important for early detection. When symptoms do occur, they are usually related to bleeding or changes in bowel function.
Rectal bleeding is a common sign, appearing as red streaks in stool or causing black stool. Changes in bowel habits, such as new onset constipation or diarrhea lasting over a week, can also indicate polyps. Other potential indicators include abdominal pain or cramping, especially with larger polyps, and iron deficiency anemia from slow, unseen blood loss.
When Diarrhea Relates to Polyps
While diarrhea can stem from various common conditions, it is an infrequent symptom of colon polyps. However, certain polyp characteristics can lead to diarrhea. Larger polyps may irritate the colon lining, potentially altering fluid absorption or secretion, which can result in changes in bowel habits including diarrhea.
A specific type of adenoma, known as a villous adenoma, is particularly associated with diarrhea. These polyps, especially when large and located in the rectum or lower colon, can produce significant mucus. This excessive mucus secretion can lead to watery diarrhea and, in rare cases, severe electrolyte imbalances. The fluid loss is attributed to increased mucus production and altered ion transport within the colon.
Screening and Next Steps
If you experience persistent changes in bowel habits, including diarrhea, or any other concerning symptoms, consult a healthcare professional. Such symptoms can indicate various conditions, and medical evaluation helps determine the underlying cause.
Screening for colon polyps is crucial for early detection and prevention of colorectal cancer. Colonoscopy is considered the gold standard, allowing direct visualization of the entire colon and immediate removal of any polyps found during the procedure. Other screening methods include stool-based tests and virtual colonoscopy, but a positive result often necessitates a follow-up colonoscopy. Regular screening, as recommended by your doctor based on age and individual risk factors, significantly reduces the risk of polyps progressing to cancer.