Gallstones may be found during tests that evaluate abdominal pain or during routine ultrasound exams to monitor a pregnancy. The health professional will ask questions about your medical history and your symptoms and will do a physical exam. Although your medical history and a physical exam may suggest that you have gallstones, other tests can confirm the diagnosis. Tests for gallstones include:

• Abdominal ultrasound. An abdominal ultrasound is the best test to confirm gallstones. It is 95% accurate.¹ In this test, a technologist moves a wand across your belly to create pictures on a video monitor. This test may reveal other problems with the gallbladder or bile ducts. It also can help diagnose other conditions that may cause symptoms similar to gallstones, such as infection, a tumor, or inflammation of the pancreas (pancreatitis). See an ultrasound image of a gallstone. Often this is the only test needed to find and evaluate gallstones.
• Hepatobiliary (HIDA) scan. If your gallbladder looks normal on an abdominal ultrasound, but your doctor still thinks that you may have a problem, your doctor may request a HIDA scan. In this test, a health professional injects a special radioactive dye into a vein in your arm and takes pictures to see whether the gallbladder is working normally. This test can also reveal other problems, such as blocked bile ducts (bile ducts are tubes attached to your gallbladder).
• Endoscopic retrograde cholangiopancreatogram (ERCP). This test is used if your doctor thinks that you may have a gallstone in one of the ducts that connect your liver with your gallbladder, pancreas, and small intestine. In an ERCP, a doctor gently moves a flexible, lighted viewing instrument called an endoscope down the throat and through your stomach to examine the tubes that drain your liver, gallbladder, and pancreas. If a gallstone is blocking your common bile duct, the doctor can sometimes remove the stone with instruments inserted through the endoscope.

Blood tests. Tests such as a complete blood count and tests for liver function and pancreatitis can help a health professional evaluate symptoms of abdominal pain that may be caused by gallstones. The tests may be able to detect whether your symptoms are being caused by a condition other than gallstones.

Other tests include:

• Abdominal X-ray. Abdominal X-rays can only detect some gallstones, so this test is not usually used to look for them.
• Endoscopic ultrasound (EUS). This test can be used to see gallstones in the common bile duct. A doctor gently moves a thin, flexible, lighted viewing instrument (endoscope) with an ultrasound probe down the throat and through your stomach to examine the tubes that drain the liver, gallbladder, and pancreas.
• Magnetic resonance cholangiogram (MRC). This test uses a magnetic field and pulses of radio wave energy (MRI) to provide pictures of organs and structures inside the abdomen. Doctors can use an MRC to locate gallstones before surgery to remove the gallbladder (laparoscopic cholecystectomy) or to detect problems with the bile duct or gallbladder. Although you won't need to swallow an endoscope for this test like you do for an ERCP, doctors cannot use this procedure to remove gallstones from a blocked duct.