Diagnosis

Your doctor will take a medical history, including a history of previous bleeding, conduct a physical exam and possibly order tests. Tests might include:

• Blood tests. You may need a complete blood count, a test to see how fast your blood clots, a platelet count and liver function tests.
• Stool tests. Analyzing your stool can help determine the cause of occult bleeding.
• Nasogastric lavage. A tube is passed through your nose into your stomach to remove your stomach contents. This might help determine the source of your bleed.
• Upper endoscopy. This procedure uses a tiny camera on the end of a long tube, which is passed through your mouth to enable your doctor to examine your upper gastrointestinal tract.
• Colonoscopy. This procedure uses a tiny camera on the end of a long tube, which is passed through your rectum to enable your doctor to examine your large intestine and rectum.
• Capsule endoscopy. In this procedure, you swallow a vitamin-size capsule with a tiny camera inside. The capsule travels through your digestive tract taking thousands of pictures that are sent to a recorder you wear on a belt around your waist. This enables your doctor to see inside your small intestine.
• Flexible sigmoidoscopy. A tube with a light and camera is placed in your rectum to look at your rectum and the last part of the large intestine that leads to your rectum (sigmoid colon).
• Balloon-assisted enteroscopy. A specialized scope inspects parts of your small intestine that other tests using an endoscope can't reach. Sometimes, the source of bleeding can be controlled or treated during this test.
• Angiography. A contrast dye is injected into an artery, and a series of X-rays are taken to look for and treat bleeding vessels or other abnormalities.
• Imaging tests. A variety of other imaging tests, such as an abdominal CT scan, might be used to find the source of the bleed.

If your GI bleeding is severe, and noninvasive tests can't find the source, you might need surgery so that doctors can view the entire small intestine. Fortunately, this is rare.