Exams and Tests

Ulcerative colitis can be fairly easy to diagnose, because it normally affects only the colon and rectum. And it usually causes an obvious change in daily bowel habits, such as frequent stools with blood or mucus.

Your doctor may:

• Conduct a medical history and physical exam.
• Look inside your colon and rectum with flexible sigmoidoscopy or colonoscopy. The doctor uses a small, lighted scope to look inside the intestine. In general, colonoscopy is preferred because it can be used to see the entire colon. Both procedures can be used to take a sample (biopsy) of intestinal tissue. Biopsies are collected during sigmoidoscopy or colonoscopy to see if you have ulcerative colitis. A biopsy also may be done to look for cancer.

Other exams and tests that may be used include:

• Abdominal X-ray. It provides a picture of the inside of the abdomen.
• Barium enema. It allows the doctor to examine the colon.
• Computed tomography (CT) scan or MRI. These provide detailed pictures of the inside of the body.
• Stool analysis (including a test for blood in the stool). This test looks for blood, signs of bacterial infection, parasites, or white blood cells.
• Blood and urine tests to check for anemia, inflammation, or malnutrition. An erythrocyte sedimentation rate (ESR, or sed rate) or a C-reactive protein (CRP) blood test may be done to look for infection or inflammation.

Some people have symptoms of inflammatory bowel disease (IBD), but neither Crohn's disease nor ulcerative colitis can be diagnosed. These people have a form of IBD called indeterminate colitis. Doctors believe that it has features of both Crohn's disease and ulcerative colitis.