Gastroenterology, Hepatology and Nutrition

GI Glossary

An explanation of common diagnostic tests, procedures and terms related to gastroenterology, hepatology and nutrition

          A-C             D-E              F-K             L-O             P-Z 

albumin level

A sample of blood is obtained from your child's vein. Below-normal levels of albumin (a protein made by the liver) are associated with many GI illnesses.

anorectal manometry

An anorectal manometry is a test to determine the strength of the muscles in the rectum and anus. These muscles normally tighten to hold in a bowel movement and relax when a bowel movement is passed. Anorectal manometry is helpful in evaluating constipation and other anal and rectal issues. A small tube is placed into the rectum, and then pressures inside the anus and rectum are measured. The test will give information about the strength and coordination of anal and rectal contractions.  

antroduodenal manometry

Antroduodenal or small bowel manometry provides information about the muscle and nerve activity of the stomach and small bowel. The patient may not eat for two hours and then will be given a high fat meal during the study. The test will give information about the strength and coordination of intestinal contractions. 

barium enema

A barium enema (also called a lower GI series, a contrast enema or a water-soluble enema) is a procedure that examines the rectum and the large intestine. Fluid called barium or a water-soluble contrast is given into the rectum as an enema. An X-ray of the abdomen shows strictures (narrowed areas), obstructions (blockages), and other problems.

barium study, small bowel follow through

This study is very similar to the upper GI series, but because the barium is “followed through” to the end of the small bowel, it can take several hours to complete.

barium study, upper GI series  

An upper GI series is a diagnostic test that examines the anatomy of the upper part of the digestive system — the esophagus, stomach and duodenum (the first section of the small intestine).

bilirubin level

To test your child’s bilirubin level, a sample of blood is taken from your child’s vein. Bilirubin is produced by the liver and is excreted in the bile.

capsule endoscopy

A capsule endoscopy is similar to a standard endoscopy, but instead of an endoscope (a small flexible tube) being guided through the patient’s mouth and throat, the patient swallows a vitamin-sized capsule that has a tiny wireless camera inside it. As the capsule travels through the patient’s digestive tract, the camera takes thousands of pictures of the esophagus, stomach and intestines. Capsule endoscopy helps doctors see inside a patient’s small intestine — an area that isn't easily reached with more-traditional endoscopy procedures.

colonic manometry

Colonic manometry is a test performed to evaluate children with issues including colonic dysmotility, constipation and stool soiling (leakage). This test measures the contractions in the colon and the rectum.


Colonoscopy (also called a lower endoscopy) is a procedure that allows the physician to view the entire length of the large intestine. It involves inserting a colonoscope, a long, flexible lighted tube, in through the anus and rectum up into the colon. The colonoscope allows the physician to see the lining of the colon, remove samples of tissue for further examination, and possibly treat some problems that are discovered.

complete blood count (CBC)

To determine a complete blood count, a sample of blood is taken from your child’s finger or vein, and the different types of blood cells in the bloodstream are counted.

computed tomography scan (CT scan)

A CT scan is a diagnostic imaging procedure. CT scans are more detailed than general X-rays. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat and organs.

DEXA bone density measurements

Dual energy X-ray absorptiometry (DEXA) is the most common method to measure a person’s bone density (strength).

electrolyte tests  

A sample of blood is taken from your child’s vein, and the amounts of minerals known as electrolytes are measured, including sodium, potassium, calcium and glucose.

endoscopic retrograde cholangiopancreatography (ERCP)

ERCP is an endoscopic procedure that allows the physician to diagnose, evaluate and sometimes treat problems in the liver, gallbladder, bile ducts and pancreas. The procedure combines X-ray and the use of an endoscope — a long, flexible, lighted tube. The scope is guided through the patient’s mouth, esophagus, stomach and duodenum (the first section of the small intestine). From the duodenum catheters can be placed into the ducts from the gall bladder, liver and pancreas to allow testing and sometimes treatment in those areas.

endoscopic ultrasound

Endoscopic ultrasound (EUS) uses both endoscopy and ultrasound to obtain information and images about your child’s digestive tract and the surrounding tissue and organs. Endoscopy is a procedure where a long flexible tube is inserted into your child’s mouth or the rectum to visualize the digestive tract. Ultrasound is a diagnostic test that uses high-frequency sound waves to produce images of your child’s organs and structures inside the body. By combining the test technologies, clinicians can get a more accurate view of your child’s condition. EUS is still a relatively new diagnostic tool and is only being used for children with certain suspected conditions.

enema, barium or contrast

See barium enema.

endoscopy, capsule

See capsule endoscopy.

endoscopy, ERCP

See endoscopic retrograde cholangiopancreatography.

endoscopy, lower

See colonoscopy.

endoscopy, upper

An upper endoscopy (also called an esophagogastroduodenoscopy or EGD) is a diagnostic test in which a doctor uses a flexible tube with a camera and light to examine your child’s throat, stomach and upper intestine. The doctor may also take small tissue samples for further testing.

esophageal manometry  

An esophageal manometry helps determine the strength of the muscles in the esophagus. It is useful in evaluating gastroesophageal reflux and swallowing abnormalities. A small tube is guided into the nostril, then passed into the throat and finally into the esophagus. Then, the pressure the esophageal muscles produce at rest is measured. 

esophageal pH monitoring

An esophageal pH monitor measures the acidity inside of the esophagus. It is helpful in evaluating gastroesophageal reflux disease (GERD). A thin plastic tube is placed into a nostril, guided down the throat and into the esophagus. The tube stops just above the lower esophageal sphincter, which is at the connection between the esophagus and the stomach. At the end of the tube inside the esophagus is a sensor that measures pH, or acidity. The other end of the tube outside the body is connected to a monitor that records the pH levels for a 12- to 24-hour period. Normal activity is encouraged during the study, and a diary is kept of symptoms experienced or activity that might be suspicious for reflux, such as gagging or coughing. The pH readings are evaluated and compared to the child’s activity for that time period.

esophagogastroduodenoscopy (EGD)

See endoscopy, upper.

fecal elastase test

The fecal elastase test measures elastase, an enzyme found in fluids produced by your child’s pancreas. Elastase digests and degrades various kinds of proteins. During this test, your child’s stool sample is analyzed for its elastase level which reflects pancreatic function. 

fecal fat test

A fecal fat test measures the amount of fat contained in your child’s stool. If the digestive tract is working properly, only small amounts of fat will be present in the stool; the rest of the fat that was in the diet will have been digested and reabsorbed by the body.

fecal occult blood test

A fecal occult blood test checks for hidden (occult) blood in the stool.

flexible sigmoidoscopy

A flexible sigmoidoscopy is an endoscopic diagnostic procedure used to see inside the sigmoid colon and rectum. It involves inserting an endoscope, a long, flexible lighted tube, in through the rectum up into the colon. The endoscope allows the physician to see the lining of the colon, remove a sample of tissue for further examination, and possibly treat some problems that are discovered.


A fundoplication is a surgery to treat reflux. The fundoplication reduces the chance that stomach contents can move up into the esophagus causing gastroesophageal reflux disease (GERD). There are various kinds of fundoplication surgeries; however, the object of each of them is to tighten the valve between the esophagus and the stomach. 

gastric emptying scan

The gastric emptying scan measures the speed and completeness of stomach (gastric) emptying. The rate of emptying can be increased or decreased in different disease states.

hydrogen breath test

A hydrogen breath test measures the amount of hydrogen in the breath, and helps diagnose several digestive problems, including lactose (and other kinds of sugar) malabsorption, and bacterial overgrowth in the small bowel. For this test it is important for your child to fast overnight, then at the test a drink will be provided with the sugar (lactose, for example) to be tested. Your child will then blow into a machine that will measure the hydrogen content in the exhaled breath. Hydrogen levels will be elevated if the sugar is malabsorbed (or in certain other diseases). The test can take several hours to complete because multiple samples of breath are needed.

impedance study

The impedance probe measures acid and non-acid reflux in the esophagus. The probe contains multiple sensors that measure reflux. You will be asked to keep a diary during your child’s study. It is important to keep a patient diary for two reasons: to obtain critical information about your child’s symptoms, meals and medications, and to ensure the probe’s function.

liver biopsy

A liver biopsy helps diagnose liver diseases. A small sample of liver tissue is obtained with a special biopsy needle and examined for abnormalities.

liver enzymes

To test liver enzymes, a sample of blood is taken from your child’s vein, and the amounts of enzymes in the bloodstream are measured.

liver transplant

Children with acute or chronic liver disease, certain metabolic diseases, or liver cancers may require liver transplantation. This is a major operation performed by a team of surgeons to remove the liver and replace it with liver from a donor. For more information, see CHOP’s liver transplant program.

lower endoscopy

See colonoscopy

lower GI series

See barium enema.

manometry, anorectal

See anorectal manometry.

manometry, colonic

See colonic manometry.

manometry, esophageal

See esophageal manometry.

manometry, small bowel

See antroduodenal manometry.

MRI (magnetic resonance imaging)

An MRI is a diagnostic procedure that uses a combination of large magnets, radio waves, and a computer to produce detailed images of organs and structures within the body. The test does not involve exposure to radiation. Some kinds of metal objects cannot be present in the MRI room, so children with pacemakers or metal clips or rods inside the body may not be able to have this test done. MRI has the advantage of excellent detail and no radiation, however the disadvantage is that it is noisy and takes a long time (during which time the patient must remain still). Some children will require sedation in order to remain still in the scanner.

modified barium swallowing study (also known as oropharyngeal motility study)

In a modified barium swallowing study, your child is given small amounts of liquid containing barium to drink with a bottle, spoon or cup. Barium is a chalky liquid used to coat the inside of the GI tract so it will show up on an X-ray. A series of X-rays are taken to evaluate what happens as your child swallows the liquid.

pH probe study

See esophageal pH monitoring.

prothrombin time (PT) test

This test measures the time it takes for blood to clot. Blood clotting requires vitamin K and several clotting factors (proteins) made by the liver.

resting energy expenditures

Resting energy expenditure measures the amount of calories required by your child’s body while at rest.

Sitz Marker study

The Sitz Marker study measures the movement of several small rings through the GI tract. Your child will swallow a capsule containing the rings and then abdominal X-rays are done to trace the movement of the rings through the bowel. The results of this study will tell your child's doctor how long it takes for the intestine to move stool through the large bowel (also known as the colon). There is no change in your child’s activity or diet during this test.

stool culture

A stool culture checks for the presence of abnormal bacteria in your child's stool that may cause diarrhea and/or other problems. A small sample of stool is collected and sent to a laboratory.


An ultrasound is a diagnostic imaging technique using high-frequency sound waves and a computer to create images of blood vessels, tissues and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels. Ultrasound is painless and does not use radiation, however the images are not as detailed as some other forms of imaging.

upper endoscopy

See endoscopy, upper.

upper GI series

See barium study, upper GI series.

Contact us

To schedule an appointment with CHOP’s Division of Gastroenterology, Hepatology and Nutrition, please call 215-590-3630.

Reviewed by: Gastroenterology, Hepatology and Nutrition clinical team
Date: January 2013 

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