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Ulcerative Colitis (cont.)

Ulcerative Colitis Diagnosis

A thorough physical exam and a series of tests may be required to diagnose ulcerative colitis.

Inflammatory bowel disease may mimic other conditions, and symptoms may vary widely. The correct diagnosis of ulcerative colitis may take some time. A health care professional will want to consider a variety of potential medical conditions and referral to a gastroenterologist may be required.

History: The doctor may ask the patient several questions to find out possible causes of the person's colitis. Answers to these questions will help assess the patient's condition, how to make the diagnosis and plan the treatment.

Physical exam: The doctor will examine the abdomen and other body systems. This will include performing a rectal examination to check for abnormal growths or masses and blood in the stool.

Laboratory tests: The doctor will decide which tests are needed based on the symptoms, medical history, and clinical findings. Some of the most commonly used tests are these:

  • Stool samples to check for evidence of bleeding or infection.
  • Complete blood count (CBC) to check for anemia or infection.
  • Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) which may be abnormal in an acute flare of inflammatory bowel disease. These are non-specific tests that reflect presence of inflammation within the body.
  • Electrolyte levels in the blood, especially looking for abnormalities in sodium and potassium levels, chemicals that can be lost from the body because of profuse diarrhea.
  • Albumen levels, especially in severe inflammatory bowel disease, to assess protein loss from the inflamed intestine or impairment of liver function.
  • Liver function tests


Certain X-rays and other imaging tests will further pinpoint a diagnosis of colitis. The decision as to which test to use depends upon the patient's symptoms and presentation.

  • Plain X-rays of the abdomen tend not to be helpful in the general evaluation of abdominal pain. In emergency situations, they may be done to look for bowel obstruction or abnormal locations of air due to a perforation of the bowel.
  • Contrast X-rays with fluoroscopy may be helpful in the diagnosis. Upper GI series, small bowel studies, and enemas using barium or other liquids to outline the structures of the digestive tract, while a radiologist monitors the results in real time.
  • Computerized tomography (CT) scans may be used to evaluate the digestive tract as well as other organs for a variety of diseases.


The lining of the intestine may be viewed directly by a gastroenterologist using a thin flexible camera that is inserted through the anus and threaded up the colon, known as colonoscopy. Sigmoidoscopy allows the physician to see the lower portion of the colon, while colonoscopy allows visualization of the whole of the large intestine.

Aside from evaluating the lining of the colon, with colonoscopy or sigmoidoscopy, there is the opportunity to obtain biopsies, or small pieces of tissue for examination under a microscope. These biopsies may be helpful in confirming the diagnosis of ulcerative colitis or Crohn's disease.

Medically Reviewed by a Doctor on 4/7/2016
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