Colitis Diagnosis & Testing

Your doctor will make a diagnosis based on your medical 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. Following this, the patient generally undergoes an evaluation of the colon, using one of two tests -- a sigmoidoscopy or total colonoscopy.

In addition to making the initial diagnosis, the tests your doctor performs will also help determine which type of Ulcerative Colitis you have. Each type has its own specific symptoms and associated complications. Learn more about the different Types of Colitis.

Early Tests and Exams

Your doctor will conduct a physical exam of your body and interview you to learn more about your general health, diet, family history, and environment.

Early steps in the diagnostic process can include laboratory tests of blood and fecal matter. Stool specimens are 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.

Endoscopy and Biopsy

Your doctor may recommend endoscopy, which is the use of medical instruments to visually examine the interior of your colon with a lighted tube that is inserted through the anus. Your doctor may recommend two types of endoscopic examinations: a sigmoidoscopy and a total colonoscopty.

  • Sigmoidoscopy involves the insertion of a flexible instrument into the rectum and lower colon that allows the doctor to visualize the extent and degree of inflammation in these areas.
  • Total colonoscopy is a similar exam, but it visualizes the entire colon.

During these procedures, your doctor may wish to obtain a sample of affected tissue, called a biopsy. Biopsied tissues are then analyzed in pathology to determine the presence of disease.

While endoscopy and biopsy may sound invasive, modern medical technology and techniques have made these procedures virtually painless and easily accomplished during an outpatient visit.

Chromoendoscopy

Your doctor may recommend a colonoscopy to look for any polyps or pre-cancerous changes in the setting of colitis.  Chromoendoscopy is a technique of spraying a blue liquid dye during the colonoscopy in order to increase the ability of the endoscopist specialist to detect slight changes in the lining of your intestine.  The technique may identify early or flat polyps which can be biopsied or removed.  It is common to have blue bowel movements for a short time following this procedure.