Gastrointestinal Bleeding

Diagnosis of Gastrointestinal Bleeding

Mayo Clinic uses a variety of procedures to investigate obscure GI bleeding. Results from one procedure determine the next procedure to use until the source of the bleeding is found and can be treated.

In about 25 percent of cases, the source of the blood loss is in the small bowel. Lesions on blood vessels in the small bowel are the most common source of bleeding.

Endoscopy
In an endoscopic procedure, a physician inserts a thin, lighted, camera-tipped tube (endoscope) either through the mouth or rectum to look inside the body. The patient is sedated before the procedure. An advantage of this examination is that instruments can sometimes be operated through the endoscope to treat or biopsy polyps, lesions or tumors as they are found. A disadvantage is that the endoscope cannot reach the entire GI tract.

To examine the upper GI tract,either esophagogastroduodenoscopy (EGD) or push enteroscopy may be used. Both procedures go through the mouth. The main difference between the two procedures is that push enteroscopy uses a special, longer endoscope (enteroscope) that can be pushed further into the small intestine, whereas EGD only reaches as far as the duodenum (first segment of the small intestine after the stomach).

To examine the lower GI tract, colonoscopy is used, with access through the rectum.

Capsule endoscopy
Capsule endoscopy is a relatively new noninvasive procedure that views the gastrointestinal tract via a tiny camera contained in a capsule swallowed by the patient. This has the advantage of showing the entire length of the small intestine rather than the few feet that colonoscopy or push enteroscopy can view on either end. There is no discomfort and sedation isn't necessary. However, the camera can't be controlled and lesions can't be treated or biopsied at the time that they're discovered.

Multiphase CT enterography
Multiphase CT enterography (MCTE) is a new noninvasive procedure that uses very fast CT scanning to obtain detailed cross-sectional images of the abdomen. Mayo Clinic doctors have found MCTE to be a helpful complement to capsule endoscopy in identifying bleeding sources.

Double balloon enteroscopy
Double balloon enteroscopy is a relatively new technology that has the advantage of being able to treat a bleeding problem at the time it's found. A physician inserts a flexible tube equipped with two tiny balloons and a small camera through the mouth down into the intestine. The balloons are periodically inflated as they travel down the intestines, in order to pull up the segment of the intestine just examined (like a curtain along a rod) so that the next segment can be viewed. If a bleeding source is found, instruments can be inserted through the scope to snare or cauterize it. The process is repeated until the majority of the small intestine has been examined. The patient is sedated during the procedure.

Bleed scan (also called a gastrointestinal nuclear scan)
A physician injects a radioactive substance (tracer) into a patient's vein and then observes its passage through the body with a special camera to see where blood may be pooling.

Angiography
A physician threads a catheter (thin tube) into an artery. Contrast dye is injected and a series of X-rays taken to look for abnormalities in the blood vessels.

Intraoperative endoscopy
A physician opens the body with an incision and inserts an endoscope to locate and treat a lesion. The patient receives general anesthesia for the procedure.

Small bowel barium X-ray
An X-ray of the small bowel, using barium for contrast. Mayo Clinic infrequently uses this procedure for diagnosing obscure GI bleeding as it's generally less successful compared to other newer procedures.