Diagnosis of GI Bleeding
How do doctors diagnose GI bleeding?
To diagnose gastrointestinal (GI) bleeding, a doctor will first find the site of the bleeding based on your medical history—including what medicines you are taking—and family history, a physical exam, and diagnostic tests.
During a physical exam, a doctor most often
- examines your body
- listens to sounds in your abdomen using a stethoscope
- taps on specific areas of your body
Depending on your symptoms, your doctor will order one or more diagnostic tests to confirm whether you have GI bleeding and, if so, to help find the source of the bleeding.
What tests do doctors use to diagnose GI bleeding?
Your doctor may perform the following tests to help diagnose the cause of your GI bleeding.
Lab tests to help diagnose the cause of your GI bleeding include:
Stool tests. A stool test is the analysis of a sample of stool. Your doctor will give you a container for catching and storing the stool. You will receive instructions on where to send or take the kit for analysis. Stool tests can show occult bleeding.
Blood tests. A health care professional may take a blood sample from you and send the sample to a lab to test. The blood test can help determine the extent of your bleeding and whether you have anemia.
A gastric lavage is a procedure in which a doctor passes a tube through your nose or mouth into your stomach to remove your stomach contents to determine the possible location of your GI bleeding. A doctor may also use gastric lavage to help prepare for another diagnostic test or, most often, for acute, severe bleeding. The doctor performs this procedure in an outpatient center or a hospital. You most often receive a liquid anesthetic to numb your throat.
Endoscopy procedures involve a doctor examining a hollow passage in your body using a special instrument. An endoscopy procedure may help your doctor see if and where you have GI bleeding and the bleeding’s cause. Doctors most often use upper GI endoscopy and colonoscopy to test for acute GI bleeding in the upper and lower GI tracts.4,5
Upper GI endoscopy. In an upper GI endoscopy, your doctor feeds an endoscope down your esophagus and into your stomach and duodenum. A trained specialist performs the procedure at a hospital or an outpatient center. You most often receive a liquid anesthetic to numb your throat and a light sedative to help you stay relaxed and comfortable during the procedure.
Capsule endoscopy. In capsule endoscopy, you swallow a capsule containing a tiny camera that allows your doctor to see inside your GI tract. You don’t need anesthesia for this procedure. The test begins in a doctor’s office, where you swallow the capsule. As the capsule passes through your GI tract, the camera will record images that your doctor later downloads and reviews. The camera capsule leaves your body during a bowel movement.
Colonoscopy. Colonoscopy is a procedure in which a doctor uses a long, flexible, narrow tube with a light and tiny camera on one end, called a colonoscope or scope, to look inside your rectum and colon. A trained specialist performs a colonoscopy in a hospital or an outpatient center. You will receive sedatives, anesthesia, or pain medicine during the procedure. The doctor can see and treat any GI bleeding during a colonoscopy.
Flexible sigmoidoscopy. Flexible sigmoidoscopy is a procedure in which a doctor uses a flexible, narrow tube with a light and tiny camera on one end, called a sigmoidoscope or scope, to look inside your rectum and sigmoid colon and treat any bleeding. A trained specialist performs a flexible sigmoidoscopy at a doctor’s office, a hospital, or an outpatient center. You do not need anesthesia for this procedure.
To help find the cause of your GI bleeding, your doctor may order one or more of the following imaging tests. You do not need anesthesia for these tests.
Abdominal CT scan. An abdominal computerized tomography (CT) scan uses a combination of x-rays and computer technology to create images of your GI tract. An x-ray technician performs the procedure in an outpatient center or a hospital. A radiologist reads and reports on the images.
Lower GI series. A lower GI series is a procedure in which a doctor uses x-rays and a chalky liquid called barium to view your large intestine. An x-ray technician and a radiologist perform a lower GI series at a hospital or an outpatient center.
Upper GI series. An upper GI series is a procedure in which a doctor uses x-rays, fluoroscopy, and a chalky liquid called barium to view your upper GI tract. An x-ray technician and a radiologist perform an upper GI series at a hospital or an outpatient center.
Angiogram. An angiogram is a special kind of x-ray in which a radiologist threads a catheter through your large arteries. The radiologist performs the procedure and interprets the images in a hospital or an outpatient center. You may receive a light sedative to help you stay relaxed and comfortable during the procedure.
Radionuclide scan. A radionuclide scan can help your doctor find the cause of your GI bleeding. A specially trained technician performs this scan in an outpatient center or a hospital. The technician injects a mixture of your blood and radioactive material into your body to highlight the area in your body that is bleeding. The dose of radioactive chemicals is small, so the chance of it causing damage to your cells is low. A special camera takes pictures that highlight the radioactive material.
Procedures to examine the GI tract
If none of the other tests help your doctor diagnose the source of your GI bleeding, a surgeon may perform one of the following operations to examine your GI tract:
Laparotomy. During a laparotomy, a surgeon will make a single cut in your abdomen and explore the abdomen. During the operation, the surgeon can treat the problems that cause the bleeding. You will receive general anesthesia.
Laparoscopy. During a laparoscopy, a surgeon uses a laparoscope to make several small cuts in your abdomen. The surgeon inserts special tools and a camera to try to locate and treat the source of the bleeding. You will receive general anesthesia.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.