Digestive Disease Diagnostic Tests and Procedures

Colonoscopy

Colonoscopy (koh-luh-NAH -skuh-pee) lets the physician look inside your entire large intestine, from the lowest part, the rectum, all the way up through the colon to the lower end of the small intestine. The procedure is used to diagnose the causes of unexplained changes in bowel habits. It is also used to look for early signs of cancer in the colon and rectum. Colonoscopy enables the physician to see inflamed tissue, abnormal growths, ulcers, bleeding, and muscle spasms.

For the procedure, you will lie on your left side on the examining table. You will probably be given pain medication and a mild sedative to keep you comfortable and to help you relax during the exam. The physician will insert a long, flexible, lighted tube into your rectum and slowly guide it into your colon. The tube is called a colonoscope (koh-LON-oh-skope). The scope transmits an image of the inside of the colon, so the physician can carefully examine the lining of the colon. The scope bends, so the physician can move it around the curves of your colon. You may be asked to change position occasionally to help the physician move the scope. The scope also blows air into your colon, which inflates the colon and helps the physician see better.

If anything unusual is in your colon, like a polyp or inflamed tissue, the physician can remove a piece of it using tiny instruments passed through the scope. That tissue (biopsy) is then sent to a lab for testing. If there is bleeding in the colon, the physician can pass a laser, heater probe, or electrical probe, or inject special medicines, through the scope and use it to stop the bleeding.

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

Colonoscopy takes 30 to 60 minutes. The sedative and pain medicine should keep you from feeling much discomfort during the exam. You will need to remain at the physician's office for 1 to 2 hours until the sedative wears off.

Preparation

Your colon must be completely empty for the colonoscopy to be thorough and safe. To prepare for the procedure you may have to follow a liquid diet for 1 to 3 days beforehand. A liquid diet means fat-free bouillon or broth, Jell-O^®, strained fruit juice, water, plain coffee, plain tea, or diet soda. You may need to take laxatives or an enema before the procedure. Also, you must arrange for someone to take you home afterward--you will not be allowed to drive because of the sedatives. Your physician may give you other special instructions.

Sigmoidoscopy

Sigmoidoscopy (SIG-moy-DAH-skuh-pee) 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 colon. Physicians may use this procedure to find the cause of diarrhea, abdominal pain, or constipation. They also use sigmoidoscopy to look for early signs of cancer in the colon and rectum. With sigmoidoscopy, the physician can see bleeding, inflammation, abnormal growths, and ulcers.

For the procedure, you will lie on your left side on the examining table. The physician will insert a short, flexible, lighted tube into your rectum and slowly guide it into your colon. The tube is called a sigmoidoscope (sig-MOY-duh-skope). 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 your 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.

Sigmoidoscopy takes 10 to 20 minutes. During the procedure, you might feel pressure and slight cramping in your lower abdomen. You will feel better afterwards when the air leaves your colon.

Preparation

The colon and rectum must be completely empty for sigmoidoscopy to be thorough and safe, so the physician will probably tell you to drink only clear liquids for 12 to 24 hours beforehand. A liquid diet means fat-free bouillon or broth, Jell-O^®, strained fruit juice, water, plain coffee, plain tea, or diet soda. The night before or right before the procedure, you may also be given an enema, which is a liquid solution that washes out the intestines. Your physician may give you other special instructions.

Upper Endoscopy

Upper endoscopy enables the physician to look inside the esophagus, stomach, and duodenum (first part of the small intestine). The procedure might be used to discover the reason for swallowing difficulties, nausea, vomiting, reflux, bleeding, indigestion, abdominal pain, or chest pain. Upper endoscopy is also called EGD, which stands for esophagogastroduodenoscopy (eh-SAH-fuh-goh-GAS-troh-doo-AH-duh-NAH-skuh-pee).

For the procedure you will swallow a thin, flexible, lighted tube called an endoscope (EN-doh-skope). Right before the procedure the physician will spray your throat with a numbing agent that may help prevent gagging. You may also receive pain medicine and a sedative to help you relax during the exam. The endoscope transmits an image of the inside of the esophagus, stomach, and duodenum, so the physician can carefully examine the lining of these organs. The scope also blows air into the stomach; this expands the folds of tissue and makes it easier for the physician to examine the stomach.

The physician can see abnormalities, like ulcers, through the endoscope that don't show up well on x-rays. The physician can also insert instruments into the scope to remove samples of tissue (biopsy) for further tests.

Possible complications of upper endoscopy include bleeding and puncture of the stomach lining. However, such complications are rare. Most people will probably have nothing more than a mild sore throat after the procedure.

The procedure takes 20 to 30 minutes. Because you will be sedated, you will need to rest at the physician's office for 1 to 2 hours until the medication wears off.

Preparation

Your stomach and duodenum must be empty for the procedure to be thorough and safe, so you will not be able to eat or drink anything for at least 6 hours beforehand. Also, you must arrange for someone to take you home--you will not be allowed to drive because of the sedatives. Your physician may give you other special instructions.

Upper GI Series

The upper gastrointestinal (GI) series uses x-rays to diagnose problems in the esophagus, stomach, and duodenum (first part of the small intestine). It may also be used to examine the small intestine. The upper GI series can show a blockage, abnormal growth, ulcer, or a problem with the way an organ is working.

During the procedure, you will drink barium, a thick, white, milkshake-like liquid. Barium coats the inside lining of the esophagus, stomach, and duodenum and makes them show up more clearly on x-rays. The radiologist can also see ulcers, scar tissue, abnormal growths, hernias, or areas where something is blocking the normal path of food through the digestive system. Using a machine called a fluoroscope, the radiologist is also able to watch your digestive system work as the barium moves through it. This part of the procedure shows any problems in how the digestive system functions, for example, whether the muscles that control swallowing are working properly. As the barium moves into the small intestine, the radiologist can take x-rays of it as well.

An upper GI series takes 1 to 2 hours. It is not uncomfortable. The barium may cause constipation and white-colored stool for a few days after the procedure.

Preparation

Your stomach and small intestine must be empty for the procedure to be accurate, so the night before you will not be able to eat or drink anything after midnight. Your physician may give you other specific instructions.

Lower GI Series

A lower gastrointestinal (GI) series uses x-rays to diagnose problems in the large intestine, which includes the colon and rectum. The lower GI series may show problems like abnormal growths, ulcers, polyps, and diverticuli.

Before taking x-rays of your colon and rectum, the radiologist will put a thick liquid called barium into your colon. This is why a lower GI series is sometimes called a barium enema. The barium coats the lining of the colon and rectum and makes these organs, and any signs of disease in them, show up more clearly on x-rays. It also helps the radiologist see the size and shape of the colon and rectum.

You may be uncomfortable during the lower GI series. The barium will cause fullness and pressure in your abdomen and will make you feel the urge to have a bowel movement. However, that rarely happens because the tube the physician uses to inject the barium has a balloon on the end of it that prevents the liquid from coming back out.

You may be asked to change positions while x-rays are taken. Different positions give different views of the intestines. After the radiologist is finished taking x-rays, you will be able to go to the bathroom. The radiologist may also take an x-ray of the empty colon afterwards.

A lower GI series takes about 1 to 2 hours. The barium may cause constipation and make your stool turn gray or white for a few days after the procedure.

Preparation

Your colon must be empty for the procedure to be accurate. To prepare for the procedure you will have to restrict your diet for a few days beforehand. For example, you might be able to drink only liquids and eat only nonsugar, nondairy foods for 2 days before the procedure; only clear liquids the day before; and nothing after midnight the night before. A liquid diet means fat-free bouillon or broth, Jell-O^®, strained fruit juice, water, plain coffee, plain tea, or diet soda. To make sure your colon is empty, you might be given a laxative or an enema before the procedure. Your physician may give you other special instructions.

Source: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, June 1998