I assume your doctor sent you for the HIDA scan because your abdominal pain raised her suspicion of gallstones, yet none were found on an ultrasound of your abdomen. In this case, the health of the gallbladder is assessed by measuring its ability to contract and squeeze out bile.

Your HIDA scan measured the "ejection fraction" of your gallbladder. Once the gallbladder is filled with HIDA (a radioactive substance), the hormone cholecystokinin is injected into a vein. The cholecystokinin stimulates the gallbladder into emptying out the HIDA. Healthy gallbladders squeeze out at least 35% of the HIDA. Your HIDA test was abnormal because only 8% of the HIDA left your gallbladder.

The decision to proceed with gallbladder surgery to relieve your pain should hinge on more than a single test.

Most important is the impression of your doctor after she considers your symptoms and performs a physical exam.

Pain typical of so called "biliary colic" is felt just below the right rib cage. It comes shortly after eating and may spread to the right shoulder and back. Nausea and sweating sometimes join the pain. The area will feel tender when pressed at the time of an attack.

Biliary colic is most often related to gallstones that get stuck in the bile duct. Sometimes people experience episodes of biliary colic but don’t have gallstones. The HIDA scan can be abnormal, similar to your result.

If you don’t have gallstones, surgery may not relieve your symptoms. The likelihood that surgery will give long-term relief from symptoms of "acalculous" (meaning without stones) biliary pain is between 65% and 80%.

Acalculous biliary pain can actually get better on its own. The reasons aren’t clear. As many as 50% of patients become pain-free without having an operation. So it is really a decision to be made with your doctor, who can also assess your overall risk for surgery.