Oral cholecystogram is an x-ray imaging procedure used to examine the gallbladder, a sac-like organ in the right upper abdomen that stores bile before it is released through the bile ducts into the small intestines to help digest fat.

The test is performed in a hospital radiology department or in the health care provider's office by an X-ray technician. The night before the test, you swallow 6 tablets (one at a time) that contains the contrast medium. At the hospital, you will lie on the X-ray table and will be asked to assume various positions.

The health care provider may examine the gallbladder with a fluoroscope (a type of X-ray that projects the image onto a TV-like monitor). Then you may be asked to drink a high-fat formula that will cause the gallbladder to contract and release some bile. X-ray images will then be taken at timed intervals.

The health care provider must be notified if you are pregnant or allergic to x-ray contrast material.

The day before the test you will be asked to eat a high-fat meal (eggs, butter, milk, salad oils, or fatty meats) at noon. That evening, eat a low-fat meal (fruits, vegetables, bread, tea or coffee, and only lean meat).

Two hours after the low-fat meal, take 6 tablets, one at a time, which contain the contrast medium. After taking the tablets, consume no fluids until after the test.

There is little or no discomfort from the test, although you will probably be hungry and thirsty. Some people experience side effects from the contrast material. There is a slight chance of developing diarrhea.

The test is used to help in diagnosing disorders of the liver and gallbladder, including gallstones and tumors.

Abnormal results may show gallstones, tumors, inflammation, and cholesterol polyps (a benign, non-cancerous, tumor growing from the mucous membrane).

Additional conditions under which the test may be performed include the following:

• Acute cholecystitis
• Chronic cholecystitis

There is a chance of an allergic reaction to the contrast material.

There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits. Pregnant women and children are more sensitive to the risks of x-rays.

If you have a history of severe kidney or lung damage, you are at increased risk of injury or side effects from the procedure. In those cases, the gallbladder ultrasound is more often used instead of the x-ray examination.

Ultrasound and MRI examination of the gallbladder has largely replaced Oral cholecystogram for imaging, especially in patients with diseased livers. For functional evaluation of the gallbladder, a nuclear medicine HIDA scan may instead be performed.