Gastroenterology

Capsule endoscopy is a term used to describe a miniature capsule used to record images through the digestive tract for use in medicine. The capsule is a camera with the size and shape of a pill used to visualize the gastrointestinal tract. The procedure was approved by the U.S. Food and Drug Administration in 2001. It is an imaging device for the detection of gastrointestinal diseases.

Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis (e.g. ulceration, polyps) and grants the opportunity for biopsy or removal of suspected lesions.

Virtual colonoscopy, which uses 2D and 3D imagery reconstructed from computed tomography (CT) scans or from nuclear magnetic resonance (MR) scans, is also possible, as a totally non-invasive medical test, although it is not standard and still under investigation regarding its diagnostic abilities. Furthermore, virtual colonoscopy does not allow for therapeutic maneuvers such as polyp/tumor removal or biopsy nor visualization of lesions smaller than 5 millimeters. If a growth or polyp is detected using CT colonography, a standard colonoscopy would still need to be performed.

Colonoscopy can remove polyps smaller than one millimeter. Once polyps are removed, they can be studied with the aid of a microscope to determine if they are precancerous or not. Colonoscopy is similar to but not the same as sigmoidoscopy. The difference between colonoscopy and sigmoidoscopy is related to which parts of the colon each can examine. Sigmoidoscopy allows doctors to view only the final two feet of the colon, while colonoscopy allows an examination of the entire colon, which measures four to five feet in length. Often a sigmoidoscopy is used as a screening procedure for a full colonoscopy. In many instances a sigmoidoscopy is performed in conjunction with a fecal occult blood test (FOBT), which can detect the formation of cancerous cells throughout the colon.

An esophagogastroduodenoscopy (EGD) or "upper GI" is an endoscopic procedure that allows gastroenterologists to view, take samples from and treat disorders of the esophagus, stomach and the duodenum (part of the small intestine). An endoscope is a thin, flexible tube that holds microscopic instruments and a miniature camera, which sends images to a video monitor.

An EGD is a common upper gastrointestinal tract procedure used in patients who have difficulty swallowing (dysphagia), nausea or vomiting, gastroesophageal reflux disease (GERD), Barrett's esophagus, pain in the upper abdomen or chest, or bleeding in the upper gastrointestinal tract. An endoscopic procedure is considered more precise than x-rays in diagnosing disorders of the upper gastrointestinal tract.

The EGD procedure

After you receive a mild sedative, your gastroenterologist will carefully maneuver the endoscope down your esophagus and throughout the upper gastrointestinal tract while viewing pictures on a video monitor. Several different instruments can be passed through the endoscope, including brushes to take cell samples and miniaturized surgical instruments. Sometimes air is introduced through the endoscope, which allows the gastroenterologist to better view individual structures being studied.

The procedure may take 30 to 45 minutes, or longer if endoscopic surgery is performed. Because esophagogastroduodenoscopy is a minimally invasive procedure, you will be able to return to normal activities the following day. You may experience some mild discomfort in the throat for several days, and may have bloating or flatulence over the next 24 hours from the air introduced into the upper GI tract.

Flexible sigmoidoscopy enables the physician to look at the inside of the large intestine from the rectum through the last part of the colon, called the sigmoid or descending colon. Physicians may use the procedure to find the cause of diarrhea, abdominal pain or constipation. They also use it to look for benign and malignant polyps, as well as early signs of cancer in the descending colon and rectum. With flexible sigmoidoscopy, the physician can see intestinal bleeding, inflammation, abnormal growths and ulcers in the descending colon and rectum. Flexible sigmoidoscopy is not sufficient to detect polyps or cancer in the ascending or transverse colon (two-thirds of the colon). However, although in absolute terms only a relatively small section of the large intestine can be examined using sigmoidoscopy, the sites which can be observed represent areas which are affected by diseases such as colorectal cancer most regularly, e.g., the rectum.

For the procedure, the patient must lie on his or her left side on the examining table. The physician inserts a short, flexible, lit tube into the rectum and slowly guides it into the colon. The tube is called a sigmoidoscope. The scope transmits an image of the inside of the rectum and colon, so the physician can carefully examine the lining of these organs. The scope also blows air into these organs, which inflates them and helps the physician see better.

If anything unusual is in the rectum or colon, like a polyp or inflamed tissue, the physician can remove a piece of it using instruments inserted into the scope. The physician will send that piece of tissue (biopsy) to the lab for testing.

Bleeding and puncture of the colon are possible complications of sigmoidoscopy. However, such complications are uncommon.

Flexible sigmoidoscopy takes 10 to 20 minutes. During the procedure, the patient might feel pressure and slight cramping in the lower abdomen, but he or she will feel better afterward when the air leaves the colon.