If gallstones are suspected, your GP will feel your abdomen to see if your liver or gallbladder is tender or enlarged and will arrange for you to be seen by a specialist in hospital for further investigations. These will usually include blood tests and an ultrasound scan.
Ultrasound
Most stones can be clearly seen on an ultrasound scanner. Ultrasound, the same technology used to confirm all is well in pregnancy, sends sound waves into the body. The echoes are picked up and used to build a picture of the condition of the liver. You may be asked not to eat or drink anything for about six hours before the test. A special jelly, which may feel cold, is smeared over the area and a small probe similar to a microphone is passed over your gallbladder. Ultrasound is a painless procedure.
Endoscopic retrograde cholangiopancreatography (ERCP)
Sometimes doctors do an examination known as endoscopic retrograde cholangiopancreatography, or ERCP. This gives a detailed X-ray of your pancreas and bile ducts, which is useful when stones have passed into them, especially when jaundice has developed. You will be given a sedative injection to make you feel sleepy and a little oxygen to help you breathe easily during the test. The whole test may last from 15 to 30 minutes and most people remember nothing about it afterwards because of the sedative injection. A long, thin flexible tube with a camera at the end is passed through your mouth and into your stomach and intestine. Dye is then injected and X-rays are taken. The dye passes out of your body harmlessly when you pass water.
Other tests
There are other types of examinations. One, called an oral cholecystogram, involves swallowing tablets containing dye, which is then concentrated in the gallbladder. When an X-ray is taken it will show whether gallstones are present and indicate whether the gallbladder is working properly.
Another slightly different test is a HIDA scan. An injection of a minute dose of a harmless radioactive material is given which shows up under a special camera. The radiation dose from this type of examination is no different from having an ordinary X-ray. Other scans that are used for the detection of gallstones include computerised tomography (CT) scans, magnetic resonance cholangiopancreatography (MRCP) scans and endoscopic ultrasound but these techniques are not routinely used in the majority of hospitals.