What is microscopic colitis?

Microscopic colitis is a type of inflammation of the colon, or large intestine that can cause chronic watery diarrhea. There are two main forms of microscopic colitis: lymphocytic colitis and collagenous colitis.

The condition is called microscopic colitis because the inflammation of the bowel lining is only visible when a biopsy is taken and is examined under a microscope.

Who gets microscopic colitis?

Microscopic colitis is generally diagnosed in people aged between 50 and 60; however, you can be any age. It is more common in women. It is estimated that 2-3 people in every 10,000 have microscopic colitis.

Additional risk factors include celiac disease, thyroid gland diseases,

Type 1 diabetes mellitus, and some types of arthritis. Research suggests that there may be a connection between microscopic colitis and a family history of irritable bowel syndrome.

What are the symptoms of microscopic colitis:

Microscopic colitis is not a life-threatening disease. However, it can be very debilitating and can significantly impair the quality of life of those affected.

The key characteristic is sustained, non-bloody, watery diarrhea.

Sustained (chronic) means that the diarrhea lasts for more than four weeks. The symptoms may range from mild watery diarrhea to severe diarrhea that leaves the patient unable to work. In extreme cases, the stool frequency may be up to 20 times per day. As a result of watery diarrhea, those affected may feel a sudden urge to defecate and have to rush to make it to the toilet on time.

Those affected by microscopic colitis often suffer from a constant fear of faecal incontinence. Problems controlling bowel movements (and potentially even a loss of control) may occur. In addition to watery diarrhea, some patients with microscopic colitis also report weight loss, stomach pain, and fatigue.

What causes microscopic colitis?

No one really knows what causes the inflammation of the colon found in microscopic colitis, but researchers believe that some medications, such as non-steroidal anti-inflammatory medications like diclofenac or ibuprofen can be a causative factor or a triggering factor. Other medications shown to be associated with microscopic colitis are: clozapine, sertraline, entacapone, rantidine and proton pump inhibitors like omeprazole, esompreprazole and antoprazole. Bacteria that produce toxins that irritate the lining of the colon and viruses that trigger inflammation may also cause microscopic colitis. Research has shown that microscopic colitis is more prevalent in smokers than non-smokers.

How is microscopic colitis diagnosed?

A complete medical history and physical examination can help determine whether other conditions, such as celiac disease, may be contributing to your diarrhea.

Your doctor will also ask about any medications you are taking, which may increase your risk of microscopic colitis.

A definitive diagnosis of microscopic colitis requires a colon tissue sample (biopsy) obtained during a colonoscopy. This test uses a long, thin tube with a camera on the end and an attached tissue-sampling device to examine the inside of your colon and remove a sample of tissue. In both types of microscopic colitis, cells in colon tissue have a distinct appearance when examined by a pathologist under the microscope, so the diagnosis is definite.

How is microscopic colitis treated?

For symptom control your doctor may prescribe anti-diarrhoeal medication such as loperamide or cholestyramine. If symptoms persist and you have three or more watery bowel movements per day, the recommended treatment is a type of steroid called budesonide. About 80-90 percent of people respond well to budesonide and need no further treatment.

Budesonide is used to reduce inflammation by acting on the immune system. Budesonide is released inside the intestine and acts directly on the inflamed mucosa. Only small quantities of the active substance enter into the circulatory system. Budesonide treatment should be taken for 8-12 weeks. Your Healthcare Professional will advise you on the correct dose.

Relapses are frequent with microscopic colitis, however the disease does respond well to repeat treatment with budesonide.