Digestive Health

Could Microscopic Colitis Be the Cause of Chronic Diarrhea?

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Diarrhea, characterized by loose, watery stools is a common digestive problem that usually lasts for a few days. However, if the diarrhea is chronic (and lasts for more than 4 weeks, it could be because of a condition known as microscopic colitis.  It occurs when the colon (large intestine) is inflamed and since it can only be seen under the microscope, it is called ‘microscopic colitis’.

This is a type of chronic inflammatory bowel disease (IBD) that causes inflammation in the digestive tract. Unlike other types of IBD like Crohn’s disease and ulcerative colitis, microscopic colitis is less severe. However, because it causes persistent watery diarrhea and other symptoms like cramping, nausea, etc., it can impact the quality of life. Dietary and lifestyle changes along with certain medications are known to be effective in preventing or reducing the symptoms of microscopic colitis.

Symptoms of microscopic colitis

The symptoms of microscopic colitis may often come and go, and sometimes may improve on their own. The symptoms include:

  • Non-bloody, watery diarrhea
  • Abdominal pain and cramping
  • Nausea
  • Dehydration
  • Weight loss
  • Fecal incontinence (leaking stool due to the inability to control bowel movements)

Causes and types of microscopic colitis

Microscopic colitis often occurs in women, older adults above 50 years of age, and those with autoimmune disease. Some of the causes of microscopic colitis include:

  • Autoimmune diseases like celiac disease, psoriasis, rheumatoid arthritis, and thyroid disease where the immune system attacks the body’s healthy tissue.
  • Certain medications like nonsteroidal anti-inflammatory drugs, heartburn drugs, antidepressants, drugs for heart disease or cancer can irritate the lining of the colon.
  • Bacterial or viral infections wherein bacteria produce toxins that can irritate the lining of the colon while a virus can trigger inflammation.
  • Bile acid (produced by the liver) that is not being absorbed properly can irritate the lining of the colon.

Types of microscopic colitis

  • Collagenous colitis: A thick layer of collagen forms under the epithelium (lining of the colon).
  • Lymphocytic colitis: There is an increase in the number of lymphocytes (white blood cells) in the epithelium.

Risk factors of microscopic colitis

The risk factors of microscopic colitis include:

  • Age: The disease is common in people between 50 and 70 years of age.
  • Gender: Women are more frequently affected by microscopic colitis than men, which seems to be associated with postmenopausal hormone therapy.
  • Genetic factors: A family history of irritable bowel syndrome is known to be associated with microscopic colitis.
  • Smoking: Research shows a link between tobacco smoke and microscopic colitis.

Diagnosis of microscopic colitis

The diagnosis of microscopic colitis primarily involves a physical examination, review of symptoms, and the use of medications, if any. The doctor may recommend some tests that include:

  • Blood tests
  • Stool tests
  • Imaging tests like computed tomography (CT), magnetic resonance imaging (MRI), and upper GI (upper gastrointestinal tract radiography)

The most frequently used test to confirm the diagnosis of microscopic colitis is colonoscopy with a biopsy. The cells of the colon have a distinct microscopic appearance that helps make a definite diagnosis.

Treatment of microscopic colitis

Microscopic colitis usually resolves on its own. However, the disease can cause recurrent episodes of symptoms. When symptoms are persistent and severe, one may require treatment.

The treatment plan for microscopic colitis may include:

  • Quitting smoking
  • Changing any medication that may be causing the disease
  • Changing the diet to improve the symptoms
  • Taking medicines to treat the disease

Dietary changes

  • Eating a low-fat and low-fiber diet may help improve diarrhea symptoms.
  • Avoiding milk and milk products if one has lactose intolerance
  • Eliminating gluten-containing foods and drinks if one has celiac disease
  • Limiting caffeine and artificial sweeteners
  • Avoiding or limiting alcohol intake


  • Corticosteroids
  • Anti-diarrheal medications
  • Anti-inflammatory medications
  • Bile acid blockers
  • Medicine that suppresses the immune system
  • TNF (Tumor Necrosis Factor) inhibitors
  • Antibiotics


When medications do not work and the symptoms are severe, surgery may be recommended to remove a portion or the whole of the large intestine.

Lifestyle changes to ease microscopic colitis symptoms

  • Staying hydratedDrinking water and fluids with electrolytes (sodium or potassium) can help prevent dehydration associated with diarrhea. However, one should avoid beverages like sugary drinks, alcohol, or caffeine as these can aggravate the symptoms.
  • Adding softer and easily digestible foods to the dietIncluding bananas, melons, rice, and applesauce in the diet can help manage symptoms of microscopic colitis. Avoiding fiber-rich foods like beans and nuts is advised.
  • Eating smaller meals throughout the day: Large meals may cause bouts of diarrhea. Opting for smaller meals can ease the symptoms of microscopic colitis.
  • Eliminating foods that irritate the digestive tract: Spicy, fried, or fatty foods can irritate the digestive tract and worsen the symptoms of microscopic colitis. Hence, one must keep away from such foods.


Microscopic colitis is not a life-threatening condition but if left untreated, one may experience chronic or recurring episodes of diarrhea. Hence, it is crucial to seek medical help if one experiences watery diarrhea for more than a few days. Following certain healthy lifestyle habits such as reducing caffeine intake and eating a well-balanced and nutritious diet can help people with microscopic colitis manage their symptoms. They may also benefit from quitting smoking and limiting alcohol intake.

Talk to a gastroenterologist for any questions on digestive health including microscopic colitis.


Digestive Health

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