Microscopic colitis is a chronic disease in which abnormal reactions of the immune system cause inflammation on the inner lining of your colon. Doctors can only see this inflammation by looking at colon tissue under a microscope.
What are the complications of microscopic colitis?
Compared with other types of IBD, microscopic colitis is less likely to lead to complications. If microscopic colitis causes severe diarrhea, it may lead to weight loss and dehydration. In rare cases, microscopic colitis may cause serious complications, such as ulcers or perforation of the colon.
Symptoms may start suddenly or begin gradually and become worse over time. Symptoms may vary in severity. For example, many people with microscopic colitis have four to nine bowel movements a day, but some people with microscopic colitis may have more than 10 bowel movements a day.3,4
You may experience remission—times when you have fewer symptoms or symptoms disappear. After a period of remission, you may have a relapse—a time when symptoms return or worsen.
What causes microscopic colitis?
Doctors aren’t sure what causes microscopic colitis. Experts think the following factors may play a role in causing or increasing the risk for microscopic colitis.
To help diagnose microscopic colitis, your doctor will ask about your symptoms and medical history and will perform a physical exam. Your doctor may ask about factors that increase the risk of developing microscopic colitis, such as smoking or taking certain medicines.
Your doctor may order medical tests, such as blood and stool tests, to check for signs of conditions that cause symptoms similar to those of microscopic colitis. Conditions that cause similar symptoms include celiac disease, other types of inflammatory bowel disease (IBD), and infections.
Colonoscopy with biopsies
Doctors order a colonoscopy with biopsies to diagnose microscopic colitis and rule out other digestive conditions.
During a colonoscopy, doctors use a colonoscope or scope—a long, flexible, narrow tube with a light and tiny camera on one end—to view the lining of the colon. The colon lining most often appears normal in people who have microscopic colitis.
Doctors obtain biopsies by passing an instrument through the colonoscope to take small pieces of tissue from the lining of your colon. To diagnose microscopic colitis, a pathologist will examine the tissue under a microscope to check for signs of the disease.
Doctors order a colonoscopy with biopsies to diagnose microscopic colitis.
How do doctors treat microscopic colitis?
To treat microscopic colitis, your doctor may recommend
Doctors prescribe medicines to improve microscopic colitis symptoms.
Doctors rarely recommend surgery to treat microscopic colitis. Surgery may be an option if microscopic colitis causes severe symptoms that don’t improve after treatment with medicines.
Eating, Diet, & Nutrition
What should I eat and drink if I have microscopic colitis?
Scientists have not yet discovered dietary changes that heal microscopic colitis. However, in some cases, doctors may recommend changing what you eat and drink to help improve diarrhea symptoms. Changing what you eat and drink can also help reduce symptoms if you have another digestive disorder—such as lactose intolerance or celiac disease—in addition to microscopic colitis.
Depending on your symptoms and health conditions, doctors may recommend limiting or avoiding
foods and drinks that contain gluten if you have celiac disease
milk and milk products if you have lactose intolerance
Talk with your doctor about what foods and beverages are best for you.
Doctors may recommend changing your diet to help reduce diarrhea symptoms.
The NIDDK conducts and supports clinical trials in many diseases and conditions, including digestive diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.
What are clinical trials for microscopic colitis?
Clinical trials—and other types of clinical studies—are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.
Researchers are studying many aspects of microscopic colitis, such as risk factors for the disease and new ways to treat it.
Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.
What clinical studies for microscopic colitis are looking for participants?
You can find clinical studies on microscopic colitis at www.ClinicalTrials.gov. In addition to searching for federally funded studies, you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health does not review these studies and cannot ensure they are safe. Always talk with your health care provider before you participate in a clinical study.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank:
Adam S. Cheifetz, M.D., Beth Israel Deaconess Medical Center, and Kristin E. Burke, M.D., M.P.H., Massachusetts General Hospital