Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Inflammatory Bowel Disease Health Center

Font Size

Microscopic Colitis

Microscopic colitis is a type of inflammation of the colon, or large intestine, that can cause watery diarrhea and cramping. While it can be painful and unpleasant, it's much less severe than other types of inflammatory bowel disease.

It's called microscopic because the inflammation is too small to see with the naked eye. The only way your doctor can diagnose it is to take a sample of tissue and check it under a microscope.

There are two types of microscopic colitis:

The differences are minor and the symptoms and treatments are the same. However, the tissues of the two types of microscopic colitis look different under a microscope.

Microscopic colitis is not related to the more serious types of bowel disease, ulcerative colitis and Crohn's disease.

Microscopic colitis does not raise your risk of cancer.

Symptoms of Microscopic Colitis

The symptoms of microscopic colitis include:

The symptoms may get better and then return.

To help diagnose microscopic colitis, your doctor may ask you to have a colonoscopy or sigmoidoscopy. Both procedures use a tube with a camera on it to inspect the colon.

During the procedure, your doctor collects tissue samples that will be checked for signs of microscopic colitis.

Microscopic Colitis Causes

Experts aren't sure what causes microscopic colitis, but bacteria, toxins, or viruses are possible causes. It could also be related to a problem with your immune system. Your body may react to a false threat and start attacking the cells in your own digestive tract.

Some medications can increase your risk for microscopic colitis, including:

Anyone can get microscopic colitis. But it's more common in women and in people 45 or older. Microscopic colitis may also run in families.

Treatment for Microscopic Colitis

Sometimes, microscopic colitis goes away on its own. If not, your doctor may suggest you take these steps:

  • Avoid food or drinks that could make symptoms worse, like caffeine, dairy, and fatty foods.
  • Take fiber supplements.
  • Stop taking medication that could trigger symptoms.

If those don't work, your doctor may suggest medications:

If these treatments don't work, you may need medications to suppress the immune system, such as Imuran (azathioprine). Surgery for microscopic colitis is an option, but very few people ever need it.

For most people with microscopic colitis, treatment generally works well. Some people have relapses after stopping treatment.

WebMD Medical Reference

Reviewed by William Blahd, MD on August 17, 2015

Today on WebMD

woman with pains in abdomen
Get personalized tips.
woman in restaurant
Tips for staying active.
woman clutching at stomach
Causes, symptoms, treatments, and more.
butter curls
What to eat and avoid.
Living With Crohns Slideshow
Ulcerative Colitis Surgery Slideshow
crohns disease healthcheck
Ulcerative Colitis Health Check
Crohns Symptoms
Ulcerative Colitis Diet
Crohns Prebiotic
Supplements UC