Microscopic Colitis

What is microscopic colitis?

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Microscopic colitis is an inflammation in the large intestine (colon) that often causes persistent, watery diarrhea and other gastrointestinal symptoms. Doctors need a microscope to identify microscopic colitis, hence the name. The condition will not present during a colonoscopy or flexible sigmoidoscopy. People with microscopic colitis often experience everyday symptoms.

There are a few different variations of microscopic colitis:

  • In cases of lymphocytic colitis, colon tissue sees an increase in white blood cells (lymphocytes)
  • In cases of collagenous colitis, colon tissue develops a thick layer of collagen, or protein.
  • Incomplete microscopic colitis is a combination of symptoms from lymphocytic and collagenous colitis.

Each type of microscopic colitis presents similar symptoms and requires the same testing and treatment. Microscopic colitis is often treatable with the help of a gastroenterologist’s diagnosis and care plan.

What causes microscopic colitis?

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Like many gastrointestinal conditions, microscopic colitis does not have a clear, singular cause. Microscopic colitis does have potential triggers, which include:

  • Viruses. Infections can cause inflammation in the colon and other parts of the body.
  • Bile acid. If bile acid is not properly absorbed, it can cause irritation in the lining of the colon.
  • Medication. Some medications can cause colon irritation. See a full list of these medications in the risk factor section below.
  • Autoimmune diseases. Some autoimmune diseases, including rheumatoid arthritis, thyroid disease, psoriasis, type 1 diabetes, and celiac disease, can increase someone’s risk of developing microscopic colitis.
  • Bacteria. Some bacteria create toxins that irritate the lining of the colon.

What are symptoms of microscopic colitis?

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Microscopic colitis causes a variety of symptoms. These symptoms persist for some people, while other people might experience symptoms that fade and recur over time. Symptoms of microscopic colitis include:

  • nausea
  • persistent, watery diarrhea
  • weight loss
  • dehydration
  • abdominal cramps, bloating, or pain
  • fecal incontinence
  • bile acid malabsorption

The primary symptom of microscopic colitis is persistent, watery diarrhea. Any of these symptoms, including diarrhea, could be a result of different gastrointestinal conditions. It is important to consult a doctor after experiencing abnormal gastrointestinal symptoms to figure out an appropriate care plan.

Are there any risk factors or groups for microscopic colitis?

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Some groups of people are more likely to contract microscopic colitis than others. Risk factors or groups for microscopic colitis include:

  • Being a woman. Some research points to increased risk of microscopic colitis as a result of post-menopausal hormone therapy.
  • Being over the age of 50. People aged 50 to 70 are most likely to develop microscopic colitis.
  • Smoking. Some studies suggest an association between microscopic colitis and smoking tobacco.
  • Having a family history of irritable bowel syndrome (IBS). Though microscopic colitis is not necessarily hereditary, a family history of IBS could increase risk of developing the condition.
  • Having an autoimmune disease. Some autoimmune diseases, like rheumatoid arthritis, thyroid disease, psoriasis, type 1 diabetes, and celiac disease, can play a role in developing microscopic colitis.

Some studies suggest a link between taking some types of medication and developing microscopic colitis. However, the scientific community does not have a consensus on whether this link actually exists. Medications that might increase risk of developing microscopic colitis are:

  • flutamide
  • proton pump inhibitors
  • paroxetine
  • topiramate
  • acarbose
  • clozapine
  • Selective Serotonin Reuptake Inhibitors (SSRIs)
  • carbamazepine
  • simvastatin
  • entacapone
  • ranitidine
  • pain relievers (aspirin, Aleve, Motrin IB, and Advil)

How is microscopic colitis diagnosed?

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A gastroenterologist will diagnose microscopic colitis using a physical exam and a discussion of symptoms. The exam and discussion will also cover whether the patient has any pre-existing conditions that might increase risk of microscopic colitis, like an autoimmune disease. The doctor will also need a list of the patient’s medications to see if any medications the patient is taking are linked to microscopic colitis.

A microscopic colitis diagnosis might also require a series of testing. Tests that can help gastroenterologists detect microscopic colitis include:

  • Flexible sigmoidoscopy. This test provides doctors with imaging of the inside the rectum and most of the sigmoid colon. The sigmoid colon is the last 2 feet of the large intestine. A flexible sigmoidoscopy involves using a thin, lighted tube to get an up-close view of the intestinal lining. This tube can also take a tissue sample during the procedure.
  • Colonoscopy. A doctor can examine the entire colon during a colonoscopy. A thin, lighted tube provides imaging of the rectum and entire colon. Similarly to the flexible sigmoidoscopy tool, this tube can also take a tissue sample during the procedure.

Imaging from a flexible sigmoidoscopy and/or colonoscopy is often not enough. Intestinal tissue can present normally during these exams. True to the name, the tissue samples need a microscopic exam before a gastroenterologist can make a definite microscopic colitis diagnosis.

Doctors might use additional testing to make a microscopic colitis diagnosis, including:

  • Blood test. This test will reveal indications of infection or anemia.
  • Stool sample analysis. This test will help eliminate infection as the cause for persistent, watery diarrhea.
  • Upper endoscopy with biopsy. This test will help eliminate celiac disease as the cause for gastrointestinal symptoms. The procedure is similar to that of a flexible sigmoidoscopy and colonoscopy, except it examines the upper digestive tract.

How is microscopic colitis treated?

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Treatment for microscopic colitis is fairly straightforward. To start, doctors might recommend lifestyle changes to alleviate symptoms. See below for a list of lifestyle changes that might reduce symptoms of microscopic colitis.

If lifestyle changes are not enough to treat microscopic colitis, then a doctor will prescribe medication. Potential medications for this condition include:

  • antibiotics
  • corticosteroids
  • sulfasalazine and mesalamine
  • Tumor Necrosis Factor (TNF) inhibitors
  • cholestyramine resin
  • anti-diarrheal medications
  • steroids
  • anti-inflammatory medications

A doctor might recommend surgery to remove all or part of the colon if the microscopic colitis becomes too severe and medication does not work.

What are lifestyle changes that could help with microscopic colitis?

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Doctors might recommend certain lifestyle changes for patients with microscopic colitis. These strategies can relieve symptoms and potentially treat mild cases of microscopic colitis.

  • Stay hydrated. Hydration can improve microscopic colitis symptoms. Water and drinks that have electrolytes are best for hydrating.
  • Graze throughout the day. Smaller meals might decrease the risk of having diarrhea. Grazing is easier on the stomach of someone with microscopic colitis.
  • Eat softer foods. Soft foods, like melons, applesauce, rice, and bananas, are easier to digest.
  • Avoid caffeine. People with microscopic colitis should avoid soda, tea, coffee, and alcohol to reduce the severity of their symptoms.
  • Avoid spicy foods. Spicy foods can irritate the digestive tract and cause further gastrointestinal discomfort.
  • Avoid foods with high fiber or lactose. Foods with high fiber, lactose, or even gluten can exacerbate symptoms of microscopic colitis. Avoid raw vegetables, starches, nuts, beans, and foods with artificial sweeteners.

Lifestyle change recommendations should come from a gastroenterologist. Though simple changes will resolve some mild cases of microscopic colitis, people experiencing microscopic colitis should still seek the care of a medical professional.

Should you see a doctor for microscopic colitis?

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A mild case of microscopic colitis that does not need medical attention. However, someone with symptoms that become more severe or persistent should schedule a doctor’s appointment as soon as possible.

Microscopic colitis presents gastrointestinal symptoms that could be attributed to a number of other conditions. It might feel confusing to determine when to see a doctor. Extreme gastrointestinal discomfort of any kind should prompt a visit to a medical professional. In any case, someone should see a doctor if they have watery diarrhea that lasts longer than a few days.

What is the outlook for people living with microscopic colitis?

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The outlook for people living with microscopic colitis is good. Some cases of microscopic colitis are mild and will go away without medical intervention. Many people with microscopic colitis will recover by taking prescribed medication. In very rare cases, patients will need surgery to treat microscopic colitis.