Ulcerative Colitis

How is Ulcerative Colitis Diagnosed?

Physicians make the diagnosis of ulcerative colitis based on the patient's clinical history, a physical examination, and a series of tests. The first goal of these tests is to differentiate ulcerative colitis from infectious causes of diarrhea. Accordingly, stool specimens are obtained and analyzed to eliminate the possibility of bacterial, viral, or parasitic causes of diarrhea. Blood tests can check for signs of infection as well as for anemia, which may indicate bleeding in the colon or rectum. Following this, the patient generally undergoes an evaluation of the colon, using one of two tests -- a sigmoidoscopy or total colonoscopy.

To perform a sigmoidoscopy, the doctor passes a flexible instrument into the rectum and lower colon. This test allows the doctor to visualize the extent and degree of inflammation in these areas. A total colonoscopy is a similar exam, but it visualizes the entire colon. Using these techniques, your physician can detect inflammation, bleeding, or ulcers on the colon wall, as well as determine the extent of disease. During these procedures, the doctor may take samples of the colon lining, called biopsies, and send these to a pathologist for further study. Ulcerative colitis can thus be distinguished from other diseases of the colon that cause rectal bleeding -- including Crohn's disease of the colon, diverticular disease, and cancer.

Another diagnostic procedure that may be used is a barium enema X-ray of the colon. After the colon is filled with barium, a chalky white solution, an X-ray is taken. The barium shows up white on the X-ray, providing a detailed picture of the colon and any signs of disease.