Oral cholecystogram is an x-ray of the gallbladder, an organ in the right upper abdomen that stores bile. The x-ray is taken before the gallbladder releases bile.

The test is done 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 six tablets (one at a time), which contain a special dye (contrast medium) that helps the gallbladder area show up better on the images.

At the hospital, you will lie on the x-ray table and will be asked to change position from time to time.

The health care provider may look at your gallbladder with a fluoroscope, an x-ray that can be immediately seen on a TV-like monitor. Then you may be asked to drink a high-fat liquid that will cause the gallbladder to contract and release some bile. X-ray images will be taken at timed intervals.

Tell your doctor 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, or fatty meats) at noon. That evening, you should eat a low-fat meal (fruits, vegetables, bread, tea or coffee, and only lean meat).

Two hours after the low-fat meal, take the six tablets, one at a time. After taking the tablets, do not drink anything 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 the use of oral cholecystogram, especially in patients with diseased livers. Another type of scan (a nuclear medicine HIDA scan) may be used to see how the gallbladder works.