Microscopic colitis is often misdiagnosed as irritable bowel syndrome. Microscopic colitis is the collective term applied to two inflammatory conditions of the colon, collagenous colitis and lymphocytic colitis.
Unlike irritable bowel syndrome, which is a functional disorder of the colon, microscopic colitis is an inflammatory bowel disease. Both conditions share similar symptoms which can lead to a misdiagnosis.
Sudden onset of diarrhea is a symptom of microscopic colitis. Stools are watery and not bloody. Typically, a person with either collagenous colitis or lymphocytic colitis can have 4 to 9 daily bowel movements. As many as 20 daily bowel movements are possible. The symptom of diarrhea becomes constant. However, some individuals may experience periods of improvement followed by worsening. Other symptoms include abdominal cramping, bloating, some weight loss, and fecal incontinence. The symptoms of irritable bowel syndrome include abdominal pain, diarrhea or constipation or a combination of both.
Microscopic colitis is diagnosed by microscopic examination of a biopsy or sample of colon tissue obtained during a colonoscopy. The inflammation is not visible during a colonoscopy. The disease can affect the entire lining of the colon or present in patches on the colon lining. Collagenous colitis is identified by layers of collagen, which is a connective protein, in the lining of the colon. It is more common in women than in men. Generally diagnosed in individuals age 50 and older, adults under 45 years old and children, ages 5 to 12 years old have been diagnosed with collagenous colitis. Lynphocytic colitis is identified by the presence of increased lymphocytes, which are white blood cells active in the response of the immune system, among the cells lining the colon. Both men and women are equally affected and typically diagnosed during the 5th decade of life.
The exact cause of microscopic colitis is not known. There are several theories. One thought is that bacteria or a virus initiated the inflammation response. Another possibility is a malfunction in the autoimmune system of an affected person. The body's immune system mistakes healthy cells as foreign. People who are diagnosed with microscopic colitis often suffer from other autoimmune disorders such as diabetes mellitus, rheumatoid arthritis, and celiac disease. Microscopic colitis has been reported to occur within families and this raises the question of genetic factors as a cause.
Treatment of collagenous and lymphocytic colitis is dependent upon the severity of the symptoms. The first approach is to control chronic diarrhea with lifestyle changes. A physician will recommend reducing fat intake and eliminating beverages which contain caffeine and foods containing lactose. Certain medications are thought to increase the risk of microscopic colitis. Avoiding nonsteroidal and anti-inflammatory medications such as ibuprofen is a recommendation. It is important to inform your physician of the medications which you are taking. If control of diarrhea is not achieved with these changes, a physician will recommend a bismuth subsalicylate such as Pepto-Bismol. If the diarrhea still persists, an anti-inflammatory medication such as sulfasalazine is prescribed. For severe cases of microscopic colitis, a corticosteroid such as Prednisone or budesonide is prescribed. Possible side effects of long term steroid use is a major concern. An ileostomy, which is the surgical removal of the last section of the small intestines, is performed in rare cases of microscopic colitis that have not responded to treatment with medications. Having microscopic colitis does not increase the risk of developing colon cancer.
Sources; www.mayoclinic.com
www.my.clevelandclinic.org
Maryann Gromisch is a registered nurse with clinical experience in medical, surgical, and critical care nursing. She has experience assisting a gastroenterologist in a private practice setting.