Microscopic colitis is an inflammation of
the large intestine (colon) that leads to persistent watery diarrhea. As its
name shows, a doctor must examine colon tissue under a microscope to identify
it. If a doctor uses a colonoscopy or flexible sigmoidoscopy, the tissue
may appear normal.
Microscopic colitis has several different
- Collagenous colitis: a thicker layer of protein develops in colon
- Lymphocytic colitis: white blood cells increase in colon tissue.
- Incomplete microscopic colitis: there are mixed features of
collagenous colitis and lymphocytic colitis.
Collagenous colitis and lymphocytic colitis
are believed to be different phases of the same condition. And all subtypes
have the same symptoms, testing and treatment.
People with microscopic colitis may have
symptoms such as:
- Chronic watery diarrhea
- Abdominal pain, cramps or bloating
- Weight loss
- Fecal incontinence
These symptoms may come and go frequently.
Moreover, they may sometimes resolve on their own.
The exact cause of this disease is still
unknown. But the following causes are considered to play a role in the
development of microscopic colitis:
- Autoimmune disease
- Bile acid
The following risk factors can increase
your risk of having microscopic colitis:
- Age. People aging 50 to 70 are most likely to develop microscopic
- Sex. Microscopic colitis is more common in women than in men.
- Genetic link. According to some researches, microscopic colitis is
associated with a family history of irritable bowel syndrome.
- Smoking. Studies have shown that microscopic colitis has relation to
tobacco smoking, especially in people aging 16 to 44.
Besides, there are links between certain
medications and microscopic colitis though whether medications cause this
disease has not been confirmed. These medications include:
- Pain reliever, such as aspirin, ibuprofen
- Proton pump inhibitors, such as lansoprazole, esomeprazole, pantoprazole
- Selective serotonin reuptake inhibitors (SSRIs) such as sertraline (Zoloft)
- Acarbose (Precose)
- Ranitidine (Zantac)
- Carbamazepine (Carbatrol, Tegretol)
- Clozapine (Clozaril, Fazaclo)
- Entacapone (Comtan)
- Paroxetine (Paxil, Pexeva)
- Simvastatin (Zocor)
Your doctor will determine whether your
diarrhea is caused by other conditions with a complete medical history and
physical examination. Since taking certain medications will increase your risk,
the doctor will also ask about the medications you are using. In order to make
a diagnosis, one or more of the following tests may be ordered:
- Flexible sigmoidoscopy
Considering that intestinal tissues may
appear normal, your doctor need to obtain a colon tissue sample during a
colonoscopy or flexible sigmoidoscopy and examine cells in it under the microscope.
Its distinct appearance under the microscope can help confirm the diagnosis.
Other tests that can help rule out other causes
- Stool sample analysis
- Blood test
- Upper endoscopy with biopsy
Diet and discontinuation of medication
Treatment for microscopic colitis often starts
with changes in diet and medications. You may be recommended to:
- Eat a low-fat, low-fiber diet
- Discontinue dairy products, gluten or both
- Avoid caffeine and sugar
- Discontinue any medication that might be a cause of your symptoms
If changes in diet and medications cannot
improve your condition, the following medications should be considered:
- Anti-diarrheal medications such as loperamide (Imodium)
- Steroids such as budesonide (Entocort EC)
- Medications that block bile acids such as cholestyramine (Prevalite)
- Anti-inflammatory medications such as mesalamine
- Medications that suppress the immune system such as mercaptopurine (Purinethol)
- TNF inhibitors such as infliximab (Remicade) and adalimumab (Humira)
Surgery is rarely necessary for microscopic colitis. But if medications cannot treat the condition, you may need a surgery to remove all or part of your colon.
Keyword: microscopic colitis.