Diarrhea is a common experience following a colonoscopy. This side effect is typically normal and expected as the digestive system adjusts after the procedure. It is a temporary condition that generally resolves on its own.
Why Diarrhea Occurs After a Colonoscopy
The primary reason for post-colonoscopy diarrhea stems from the bowel preparation process. Strong laxatives are administered to thoroughly clear the colon, ensuring a clear view for the physician. These powerful agents continue to influence bowel movements, leading to loose stools. The high-volume lavage solution rapidly moves through the bowel, increasing peristalsis and washing out luminal content.
During the colonoscopy, air or water is introduced into the colon to expand it and provide a better view. This insufflation can stimulate the bowel, contributing to increased activity and loose stools. Patients often experience bloating and gas, which can be alleviated by passing wind.
Dietary changes also play a role. Before the procedure, individuals follow a restricted diet, often consisting only of clear liquids. Reintroducing solid foods after this period can temporarily challenge the digestive system, leading to diarrhea.
The extensive bowel cleansing temporarily alters the balance of gut bacteria, known as the gut microbiota. Bowel preparation can reduce the diversity and composition of the microbiota in the short term. This disruption in the microbial community can contribute to diarrhea. While the overall composition typically recovers within 14 days, this temporary imbalance can influence digestive function.
Managing Post-Colonoscopy Diarrhea
Hydration is important when experiencing diarrhea. Drinking plenty of clear fluids, such as water, broth, and electrolyte-rich beverages, helps prevent dehydration. Avoid caffeinated and alcoholic drinks, as they can contribute to fluid loss.
Gradually reintroducing foods into your diet aids recovery. Start with bland, easily digestible options like toast, rice, bananas, and applesauce. These foods are gentle on the stomach and less likely to irritate the bowel.
Allowing the body sufficient time to rest aids recovery. Post-colonoscopy diarrhea usually resolves within 24 to 48 hours, but can last up to five days.
When to Contact Your Doctor
While diarrhea after a colonoscopy is common, certain symptoms warrant immediate medical attention. Severe abdominal pain or cramping that does not improve after passing gas should be reported to your doctor. Persistent or worsening diarrhea beyond a few days, or diarrhea accompanied by signs of dehydration, indicates a need for medical evaluation. Symptoms of dehydration include decreased urination or dizziness.
A fever, especially if it is 100.4°F (38°C) or higher, is a concerning symptom. Bloody stools, significant rectal bleeding, or passing dark, black stools are red flags requiring medical consultation. Vomiting that will not stop or vomiting blood suggests a complication.