Microscopic colitis

Microscopic colitis is inflammation to the colon, which is a part of large intestine. This condition is not related to other inflammatory bowel diseases (IBD) such as Crohn's disease or ulcerative colitis.

This condition is self-explanatory, as it is too small to identify and requires a microscope to examine, the condition is termed as microscopic colitis. Colonoscopy or flexible sigmoidoscopy usually shows no signs of inflammation on the surface of the colon and the tissue may appear normal.

There are two types of microscopic colitis; these are also considered as different phases of the condition which include:

  • Collagenous colitis, is characterized by a thick layer of protein called collagen in the colon tissue.
  • Lymphocytic colitis, is characterized by increase in white blood cells called lymphocytes in the colon tissue

Signs and symptoms

The signs and symptoms of microscopic colitis include chronic watery, non-bloody diarrhea associated with abdominal pain and cramping. Diarrhea may be continuous or episodic and you may be unable to control the bowel movements. weight loss, and feeling nauseous are also the common symptoms.


The exact cause of microscopic colitis is not clear, but researchers believe that medications such as non-steroidal anti-inflammatory drugs (NSAIDs), heartburn drugs, antidepressants which can irritate the lining of the colon cause this condition.

Bacterial toxins which irritate the lining of the colon and few viruses that trigger the inflammation can cause microscopic colitis. Pre-existing autoimmune disease such as rheumatoid arthritis or celiac disease may cause microscopic colitis. Bile acid, when not properly absorbed in the gut may irritate the lining of the colon may cause microscopic colitis.

Risk factors

Some of the factors which can increase the risk for microscopic colitis include:

  • Age and gender: microscopic colitis is common in people between 50 to 70 years of age and also more common in women than in men.
  • Autoimmune disease: You are at a risk of microscopic colitis if you are already suffering from the autoimmune disorder, such as thyroid disease, celiac disease, type-1 diabetes, rheumatoid arthritis, and psoriasis.
  • Genetics: your risk for microscopic colitis may increase if you have a family history of irritable bowel syndrome.
  • Smoking can increase your risk for microscopic colitis.

When to call the doctor?You must seek for medical care if your diarrhea lasts for more than 2 weeks and if you experience any symptoms such as weight loss, fatigue, and abdominal pain.


The condition of microscopic colitis can be successfully treated. This condition has very few chances of increasing the risk of colon cancer.



Your doctor may first take your complete medical history and asks you about the medications you use. This helps your doctor in determining if the condition is caused due to any autoimmune disease or the medications.

For a proper diagnosis of microscopic colitis, your doctor may order for biopsy test which is performed by removing the sample tissue of colon. To collect the sample of colon do so a colonoscopy or flexible sigmoidoscopy is used.

Your doctor may also order other diagnostic tests to rule out the other causes of microscopic colitis which may include:

  • Stool sample analysis- helps to rule out infection which is a cause of persistent diarrhea.
  • Blood tests- help to rule of the infections and also to identify the signs of anemia.
  • Upper endoscopy- is performed along with biopsy helps to rule out celiac disease if any.


Your doctor chooses the best suitable treatment options based on your severity:

Lifestyle changesare usually tried first during the initial stages of the disease. Your doctor may advice you to reduce the amount of fat in the diet, eliminate foods containing caffeine or lactose.

Medicationsare often used in addition to the lifestyle changes to control the symptoms of both the types of microscopic colitis. Anti-diarrheal medications which include bismuth subsalicylate and bulking agents reduce the symptoms of diarrhea. Anti-inflammatory medications such as mesalamine, sulfasalazine and steroids like budesonide reduce inflammation. Immunosuppressive agents reduce the autoimmune response.

Surgeryis performed for very extreme cases of collagenous colitis and lymphocytic colitis. Bypass of the colon or surgical removal of all or parts of the colon is performed, which is rarely recommended.

Prevention or self- management

Changes in your diet may help to relieve diarrhea associated with microscopic colitis. Drinking plenty of fluids mainly those fluids with added sodium and potassium may help as well. Avoid beverages that contain high quantity of sugar or alcohol or caffeine as it may aggravate your symptoms.

Choose easy-to-digest foods and avoid high-fiber foods initially, if your symptoms are improving, add high-fiber foods back to your diet. Avoid spicy, fatty or fried foods that may irritate your gut and any other foods that worsen your symptoms.