Microscopic Colitis: A Hidden Cause of Watery Diarrhea

Microscopic colitis is inflammation of the colon that causes chronic, watery, non-bloody diarrhea. It gets its name because the colon usually looks normal during a colonoscopy, and the inflammation only shows up when biopsies are examined under a microscope. It is most common in adults over 50, and more common in women.

Types

• Collagenous colitis: a thick band of collagen under the colon lining
• Lymphocytic colitis: extra white blood cells (lymphocytes) in the lining

Symptoms

• Frequent watery diarrhea, sometimes urgent or at night
• Belly cramping
• Weight loss or tiredness

Possible triggers

• NSAID pain relievers
• Proton pump inhibitors (acid-reducing medicines)
• Some antidepressants (SSRIs)
• Smoking
• Autoimmune conditions such as celiac disease or thyroid disease

Diagnosis

A colonoscopy with biopsies from several parts of the colon is needed. We may also test for celiac disease, which can occur alongside it.

Treatment

• Budesonide, a gut-targeted steroid, is the most effective treatment for most people
• Stopping trigger medicines when it's safe to do so
• Anti-diarrhea medicines for mild symptoms
• Other medicines for people whose symptoms keep coming back

Microscopic colitis does not raise the risk of colon cancer. See also chronic diarrhea.

Make an appointment

Our gastroenterologists in Temple City care for patients from Arcadia, San Gabriel, Pasadena, Monrovia, Monterey Park, and across the San Gabriel Valley. We accept most PPO plans (see accepted insurances), and our doctors speak English, Vietnamese, and Mandarin. Schedule an appointment or call 626-898-4560.

This article is for general education and is not a substitute for medical advice. Talk with your doctor about your own health.