Diagnosis of colonic ischemia is made through a combination of history, imaging, bloodwork, and/or endoscopic visualization of the colon.
Your doctor will begin with a thorough evaluation that includes:
- Medical history: Your doctor will ask you about symptoms you are experiencing and discuss possible risk factors.
- Physical exam: The doctor will examine you for abdominal pain or tenderness or other signs.
- Lab tests: There is no specific blood test for colonic ischemia, but a blood test can check for high white blood cell counts, a sign of infection. Your doctor may also test your stool for blood.
Other tests your doctor may order include:
Endoscopy for colon ischemia
Within this procedure, your doctor uses an endoscope (a thin, flexible tube with a lighted camera at its tip) to see inside your colon. This procedure looks for characteristics of colonic ischemia such as inflammation, ulcerations (wearing of the lining of the colon) and swelling. The doctor can perform different types of endoscopy such as:
- Sigmoidoscopy: The doctor inserts the endoscope through the rectum to examine the last two feet of the colon.
- Colonoscopy: Similar to a sigmoidoscopy, a colonoscopy also begins at the rectum but examines the entire colon.
Imaging tests for colonic ischemia
Your doctor can view the arteries supplying bloody to the colon, and the veins bringing blood back from the colon, to check for narrowed or blocked vessels. Imaging can also help rule out other causes that have similar symptoms.
For some imaging tests, you lie on a table while a technician uses sophisticated equipment to take detailed images of your abdomen and pelvis. Other tests involve inserting a thin tube into your artery to view the inside of your body and the blood vessels within your body more clearly. Your doctor will make sure you are comfortable and provide a sedative or anesthesia as necessary, depending on your procedure.
Possible tests include:
- CT scan: This imaging test uses special X-ray equipment to take cross-sectional images of your abdomen and pelvis, which are compiled into 3D images of the organs, including the small intestine, colon, and blood vessels.
- MRI scan: A large magnet and radio waves produce images of the intestines and other abdominal organs.
- Angiogram: Only used in severe cases, the doctor inserts a catheter (a long, thin tube) into an artery in your groin and carefully guides it to the aorta to inject a dye. The dye flows into the intestinal arteries, and then a technician takes X-rays to show blood flow. In many cases, the doctor can treat artery blockages during the same procedure (known as angioplasty) with or without stenting (insertion of a tiny metal mesh tube).
- CT angiogram: Only needed in severe cases, this test uses a CT scan and appropriate timing of contrast injection into your blood vessel to view the dye in your intestinal arteries.
Endoscopy is usually used when the diagnosis is unclear and biopsies are commonly taken. A biopsy is a small sample of the inner lining your large bowel that is removed during the sigmoidoscopy or colonoscopy that is assessed under the microscope for findings consistent with colonic ischemia. Biopsies can also identify other causes of your symptoms.