Upper GI (gastrointestinal) seriesAn upper GI (gastrointestinal) series is performed to assess frequent heartburn or stomach pain or to check for an ulcer or gastric reflux (food or acid coming back up the esophagus). An upper GI series is frequently requested when a patient experiences unexplained symptoms of abdominal pain, difficulty in swallowing (dysphagia), regurgitation, diarrhea, or
weight loss. It is used to help diagnose disorders and diseases of, or related to, the upper gastrointestinal tract, including cases of hiatal hernia, diverticuli, ulcers, tumors, obstruction, enteritis, gastroesophageal reflux disease, Crohn's disease, and pulmonary aspiration.
A small bowel follow-through may be done immediately after a UGI to examine the entire 20 ft(6.1 m) of the small intestine. An examination of only the throat and esophagus is called an esophagram (or barium swallow). Upper endoscopy, which uses a thin, flexible viewing tube to examine the lining of the esophagus, stomach, and upper small intestine (duodenum), has replaced the upper GI test in certain cases. See the medical test Upper Gastrointestinal Endoscopy.
What's the preparation for an upper GI series?Patients must not eat, drink, or smoke for eight hours prior to undergoing an upper GI examination. Longer dietary restrictions may be required, depending on the type and diagnostic purpose of the test. Patients undergoing a small bowel follow-through exam may be asked to take laxatives the day prior to the test. Upper GI patients are typically required to wear a hospital gown, or similar attire, and to remove all jewelry, so the camera has an unobstructed view of the abdomen.
Before the test begins, you will need to remove your clothes and put on a hospital gown. You will also need to remove any dentures and jewelry you may be wearing before the test. You may not smoke or chew gum during the test, since these activities stimulate gastric juices and slow digestion. If you are having the small bowel follow-through after the GI series, there will be periods of waiting between X-rays. The entire small bowel follow-through exam takes up to 6 hours, so bring along a book to read or material for some other quiet activity.
How is an upper GI series performed?An upper GI series takes place in a hospital or clinic setting and is performed by an x-ray technician and a radiologist. A radiologist typically is in attendance to oversee the procedure, and view and interpret the fluoroscopic pictures. Before the test begins, the patient is sometimes administered an injection of glucagon, a medication which slows stomach and bowel activity, to allow the radiologist to get a clearer picture of the gastrointestinal tract. In order to further improve the clarity of the upper GI pictures, the patient may be given a cup of baking soda crystals to swallow, which distend the stomach by producing gas.
Once these preparatory steps are complete, the patient stands against an upright x-ray table, and a fluoroscopic screen is placed in front of him. The patient will be asked to drink from a cup of flavored barium sulfate, a thick and chalky-tasting liquid that allows the radiologist to see the digestive tract, while the radiologist views the esophagus, stomach, and duodenum on the fluoroscopic screen. The patient will be asked to change positions frequently in order to coat the entire surface of the gastrointestinal tract with barium. The technician or radiologist may press on the patient's abdomen in order to spread the barium. The x-ray table will also be moved several times throughout the procedure. The radiologist will ask the patient to hold his breath periodically while exposures are being taken. The entire procedure takes approximately 30 minutes.
In some cases, in addition to the standard upper GI series, a doctor may request a detailed intestine, or small bowel, radiography and fluoroscopy series; it is also called a small bowel follow-through (SBFT). Once the preliminary upper GI series is complete, the patient will be escorted to a waiting area while the barium travels down through the rest of the small intestinal path. Every 15–30 minutes, the patient will return to the x-ray suite for additional x rays, or films. Once the barium has completed its trip down the small bowel tract, the test is completed. This procedure can take anywhere from one to four hours.
Esophageal radiography, also called a barium esophagram or a barium swallow, is a study of the esophagus only, and is usually performed as part of the upper GI series. It is commonly used to diagnose the cause of difficulty in swallowing (dysphagia) and for detecting hiatal hernia. A barium sulfate liquid, and sometimes pieces of food covered in barium, are given to the patient to drink and eat while a radiologist examines the swallowing mechanism on a fluoroscopic screen. The test takes approximately 30 minutes.
What're the risks associated with an upper GI series?Because the upper GI series is an x-ray procedure, it does involve minor exposure to ionizing radiation. Unless the patient is pregnant, or multiple radiological or fluoroscopic studies are required, the small dose of radiation incurred during a single procedure poses little risk. However, multiple studies requiring fluoroscopic exposure that are conducted in a short time period have been known, on rare occasions, to cause skin death (necrosis) in some individuals. This risk can be minimized by careful monitoring and documentation of cumulative radiation doses administered to these patients. Other risks from the procedure are relatively small and include the possibility of a bowel obstruction (from retained barium) or leakage of the barium into the abdominal cavity through an ulcer that has eroded through the stomach or intestinal wall (perforated ulcer). A special type of contrast material (Gastrografin) can be used if this possibility is suspected or if the gastrointestinal tract may be obstructed. There is some risk in using a strong laxative when there is an obstruction of the colon, ulcerative colitis, or some other diseases of the colon.