There are various kinds of GI exams. A barium enema, also known as a lower GI (gastrointestinal) exam, is a test that uses x-ray examination to view the large intestine. There are two types of this test: the single-contrasttechnique where barium sulfate is injected into the rectum in order to gain aprofile view of the large intestine; and the double-contrast (or "air contrast") technique where air is inserted into the rectum. A barium enema may be performed for a variety of reasons, including to aid in the diagnosis of colonand rectal cancer (or colorectal cancer), and inflammatory disease. Detection of polyps (a benign growth in the tissue lining of the colon and rectum), diverticula (a pouch pushing out from the colon), and structural changes in the large intestine can also be established with this test. The double-contrast barium enema is the best method for detecting small tumors (such as polyps), early inflammatory disease, and bleeding caused by ulcers.
Colonoscopy is a medical procedure in which a long, flexible, tubularinstrument called the colonoscope is used to view the entire inner lining ofthe colon (large intestine) and the rectum. It is generally recommended whenthe patient complains of rectal bleeding or has a change in bowel habits andother unexplained abdominal symptoms. The test is frequently used to test forcolorectal cancer, especially when polyps or tumor-like growths have been detected using the barium enema and other diagnostic tests. Polyps can be removed through the colonoscope and samples of tissue (biopsies) can be taken to test for the presence of cancerous cells. The test also enables the physicianto check for bowel diseases such as ulcerative colitis and Crohn's disease. It is a necessary tool in monitoring patients who have a past history of polyps or colon cancer.
An upper GI examination is a fluoroscopic examination (a type of x-ray imaging) of the upper gastrointestinal tract, including the esophagus, stomach, andupper small intestine (duodenum). It is frequently requested when a patientexperiences 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.
To begin a barium enema, the patient will lie with their back down on a tilting radiographic table in order to have x rays of the abdomen taken. After being assisted to a different position, a well-lubricated rectal tube is inserted through the anus. This tube allows the physician or assistant to slowly administer the barium into the intestine. While this filling process is closelymonitored, it is important for the patient to keep the anus tightly contracted against the rectal tube to help maintain its position and prevent the barium from leaking. This step is emphasized to the patient due to the inaccuracythat may be caused if the barium leaks. A rectal balloon may also be inflatedto help retain the barium. The table may be tilted or the patient moved to adifferent position to aid in the filling process.
As the barium fills the intestine, x rays of the abdomen are taken to distinguish significant findings.There are many ways to perform a barium enema. Oneway is that shortly after filling, the rectal tube is removed and the patientexpels as much of the barium as possible. Upon completing this, an additional x ray is taken, and a double-contrast enema may follow. If this is done immediately, a thin film of barium will remain in the intestine, and air is thenslowly injected to expand the bowel lumen. Sometimes no x rays will be takenuntil after the air is injected.
In order to conduct the most accurate barium enema test, the patient must follow a prescribed diet and bowel preparation instructions prior to the test. This preparation commonly includes restricted intake of diary products and a liquid diet for 24 hours prior to the test, in addition to drinking large amounts of water or clear liquids 12-24 hours before the test. Patients may alsobe given laxatives, and asked to give themselves a cleansing enema.
In addition to the prescribed diet and bowel preparation prior to the test, the patient can expect the following during a barium enema:
- They will be well draped with a gown as they are secured to a tilting x-ray table.
- As the barium or air is injected into the intestine, they may experience cramping pains or the urge to defecate.
- The patient will be instructedto take slow, deep breaths through the mouth to ease any discomfort.
A colonoscopy can be done either in the doctor's office or in a special procedure room of a local hospital. An intravenous (IV) line will be started in avein in the arm. The patient is generally given a sedative and a pain-killerthrough the IV line.
During the procedure, the patient will be asked to lie on his or her left side with the knees drawn up toward the abdomen. The doctor begins the procedureby inserting a lubricated, gloved finger into the anus to check for any abnormal masses or blockage. A thin, well-lubricated colonoscope will then be inserted into the anus and it will be gently advanced through the colon. The lining of the intestine will be examined through the scope. Occasionally air maybe pumped through the colonoscope to help clear the path or open the colon.If there are excessive secretions, stool, or blood that obstruct the viewing,they will be suctioned out through the scope. The doctor may press on the abdomen or ask the patient to change position in order to advance the scope through the colon.
The entire length of the large intestine can be examined in this manner. If suspicious growths are observed, tiny biopsy forceps or brushes can be inserted through the colon and tissue samples can be obtained. Small polyps can alsobe removed through the colonoscope. After the procedure, the colonoscope isslowly withdrawn and the instilled air is allowed to escape. The anal area isthen cleansed with tissues.
The procedure may take anywhere from 30 minutes to 2 hours depending on how easy it is to advance the scope through the colon. Colonoscopy can be a long and uncomfortable procedure, and the bowel cleaning preparation may be tiringand can produce diarrhea and cramping. During the colonoscopy, the sedative and the pain medications will keep the patient very drowsy and relaxed. Most patients complain of minor discomfort and pressure from the colonoscope movinginside. However, the procedure is not painful.
The doctor should be notified if the patient has allergies to any medicationsor anesthetics; any bleeding problems; or if the woman is pregnant. The doctor should also be informed of all the medications that the person is currently on and if he or she has had a barium x-ray examination recently. If the patient has had heart valves replaced, the doctor should be informed, so that appropriate antibiotics can be administered to prevent any chance of infection.The risks of the procedure will be explained to the patient before performing the procedure and the patient will be asked to sign a consent form.
It is important that the colon be thoroughly cleaned before performing the examination. Hence, before the examination, considerable preparation is necessary to clear the colon of all stool. The patient will be asked to refrain fromeating any solid food for 24 to 48 hours before the test. Only clear liquidssuch as juices, broth, and Jello are recommended. The patient is advised todrink plenty of water to avoid dehydration. The evening before the test, thepatient will have to take a strong laxative that the doctor has prescribed. Several 1 qt enemas of warm tap water may have to be taken on the morning of the exam. Commercial enemas (e.g. Fleet) may be used.
The patient will be given specific instructions on how to use the enema and how many such enemas are necessary. Generally, the procedure has to be repeated until the return from the enema is clear of stool particles. On the morningof the examination, the patient is instructed not to eat or drink anything.The preparatory procedures are extremely important since, if the colon is notthoroughly clean, the exam cannot be done.
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 patientmay 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 tospread 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 preliminaryupper 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 additionalx 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 tofour 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.
Patients must not eat, drink, or smoke for eight hours prior to undergoing anupper GI examination. Longer dietary restrictions may be required, dependingon the type and diagnostic purpose of the test. Patients undergoing a smallbowel follow-through exam may be asked to take laxatives the day prior to thetest. 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.