How Is Microscopic Colitis Diagnosed?

Microscopic colitis is an inflammatory disease of the colon. It is given the name microscopic colitis because it is identified only under a microscope, not by colonoscopy or sigmoidoscopy. It represents itself with frequent watery diarrhea, cramps in the abdomen, fecal incontinence, nausea, and weight loss. The exact cause behind the inflammation is not clear. Smoking, genetic make-up, some medicines, and auto-immune diseases are the risk factors of the disease. It is not related to ulcerative colitis and Crohn’s disease.

How Is Microscopic Colitis Diagnosed?

How Is Microscopic Colitis Diagnosed?

Microscopic colitis can be diagnosed by evaluation of complete medical history, representing symptoms and physical examination of the colon. The physician will inquire about the medicines the patient is taking especially aspirin, ibuprofen, etc. These medicines can induce microscopic colitis.

Doctor will go for a colon tissue sample taken during colonoscopy or flexible sigmoidoscopy. It can establish a definite diagnosis of microscopic colitis. In both the tests, a long thin tube with a camera at one of its end and attached tissue-sampling device is introduced into the colon to look into the colon and extract the sample. This sample from the colon is studied under a microscope to check for the distinctive appearance of microscopic colitis.

Physician may also investigate further through other diagnostic tests to rule out other diseases of the colon. These tests are-

  • Blood Test- blood tests are useful to find out any infection or anemia causing the inflammation in the colon.
  • Stool Sample Analysis- stool is tested in the laboratory to know about any infection causing diarrhea.
  • Upper GI Endoscopy With Biopsy- endoscopy of the upper respiratory tract is also done to check for celiac disease. A sample of tissues from this area is analyzed in the laboratory.
  • CT Scan and MRI Scan– it is usually done to get detailed images of intestines.

Microscopic colitis is an inflammatory disease of large intestine characterized by persistent watery diarrhea and cramps in the intestine. This inflammation can be detected only by a microscopic study of a sample extracted from the colon. Microscopic colitis is different from ulcerative colitis or Crohn’s disease. It does not get transformed into a cancerous growth.

Microscopic colitis usually affects old adults in the age of 60-70 years. Women are more likely to develop this condition than men. It usually has a family history. The people who have an autoimmune disease or who smoke cigarettes are more prone to develop this condition.

There are two types of microscopic colitis i.e. collagenous colitis and lymphocytic colitis. Both the types are identical in symptoms and treatments, but they represent a distinctive appearance.

Microscopic Colitis Causes

Microscopic colitis exact cause is not clear till today. It can be caused by microscopic organisms like bacteria, viruses or toxins. A disturbed immune system can also trigger microscopic colitis in which the body’s defense mechanism attacks the cells of the colon. Some medicines such as aspirin, non-steroidal anti- inflammatory medicines, heartburn drugs or some antidepressants can also cause microscopic colitis.

Microscopic Colitis Symptoms

The symptoms of microscopic colitis usually appear and disappear frequently. Many times, symptoms settle by its own. Sometimes symptoms may long for weeks, months or years. The symptoms of microscopic colitis are-

  • Chronic, watery diarrhea without blood in the stool
  • Frequent urging to stool
  • Pain and cramps in the abdomen which is usually mild in nature
  • Bloating
  • Involuntary passage of stool of fluid especially at night
  • Nausea
  • Weight loss
  • Loss of fluid
  • Dehydration


Microscopic colitis is a disease marked by the inflammation of a colon. It is diagnosed by microscopic study of a tissue taken from the colon which represents a distinctive appearance. Blood tests, stool sample analysis, Upper GI endoscopy with biopsy, CT scan and MRI scan is also recommended to rule out other causes of the inflammatory condition of the colon.

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