Similar to Crohn's disease, your doctor must rule out other possible causes of your symptoms prior to confirming a diagnosis of ulcerative colitis. Other medical conditions like ischemic colitis, irritable bowel syndrome (IBS), colon cancer, diverticulitis, and certain infections can produce symptoms similar to ulcerative colitis. In order to confirm a diagnosis of ulcerative colitis, your doctor may order one or more of the following medical tests and procedures.

Stool Sample

If white blood cells are present in the stool, then this could indicate an inflammatory bowel disease (IBD) like ulcerative colitis. These stool samples are also helpful in ruling out other potential issues, such as parasites, bacteria, and viruses. If you do have ulcerative colitis, then you are a greater risk of infection with the bacterium Clostridium difficile or other bowel infections.

Blood Tests

These tests can be used to check for infections or anemia. If a test can identify the presence of specific antibodies, then this could help your doctor determine the exact type of IBD you have. However, blood tests must be used in combination with other medical tests in order to confirm a diagnosis.

Colonoscopy

This procedure utilizes an advanced, flexible tube with a fitted camera that allows the doctor to examine the patient's entire colon from the inside. During your colonoscopy, doctors will also be able to extract small tissue samples (biopsies) for further laboratory analysis. In some cases, these biopsies have helped to confirm a diagnosis.

Barium Enema

After this procedure, doctors are going to be able to examine the entire large intestine with an X-ray. Barium is a contrast solution that will coat the lining of the intestine, producing a visible silhouette of the colon, rectum, and part of the small intestine. The barium is inserted into the patient's bowel with the help of an enema. However, this particular procedure can be dangerous, so it is rarely used anymore. If you are experiencing more severe UC symptoms, then flexible sigmoidoscopy combined with a CT scan is a more preferred alternative.

Flexible Sigmoidoscopy

For this procedure, doctors use an advanced, flexible tube just like in a colonoscopy, only they are examining the last portion of the patient's colon. However, this diagnostic test could miss issues that are located higher up in the colon, and it doesn't provide the full picture of what is happening to the colon. If the patient's colon is chronically inflamed, then doctors may need to go with a flexible sigmoidoscopy over a full colonoscopy.

CT Scans and X-rays

If doctors suspect that there are complications as a result ulcerative colitis, or the small intestine has become inflamed, then they may order a CT scan of the pelvis or abdomen. This imaging test is also useful in showing how much of your colon has become inflamed. In order to rule out other conditions like toxic megacolon or a perforation, doctors can take a standard X-ray of the patient's abdominal area. These medical conditions can cause severe symptoms similar to ulcerative colitis in that area.

Accurately interpreting the results of these imaging tests and procedures is the only way to make an accurate diagnosis of ulcerative diagnosis. Under certain circumstances, doctors may need to bring in a pathologist who specializes in inflammatory bowel disorders to help them interpret more obtuse biopsies.