a stonelike mass (
calculus) in the
gallbladder; the presence of gallstones is known medically as
cholelithiasis. The cause is unknown, although there is evidence of a connection between gallstones and obesity; an excess of
cholesterol in the bile appears to be of major importance. Gallstones are most common in women after pregnancy, and in both men and women past age 35. They may be present for years without causing trouble. The usual symptoms, however, are vague discomfort and pain in the upper abdomen. There may be indigestion and nausea, especially after eating fatty foods. X-rays will generally reveal the presence of gallstones, either directly or by use of a dye introduced into the gallbladder (
cholecystography).
The most common complication of gallstones occurs when one of the stones escapes from the gallbladder and travels along the common bile duct, where it may lodge, blocking the flow of bile to the intestine and causing obstructive jaundice. This condition should be corrected by surgery before the liver is damaged or problems with infection ensue.
When a gallstone travels through or obstructs a bile duct it can cause
biliary colic, with severe pain. The pain is located in the upper right quadrant of the abdomen and radiates as far as the
scapula.
morphine is usually not given to relieve the pain because it increases spasm of the biliary sphincters.
meperidine, which does not have this side effect, is the preferred medication for pain. Treatment may also include insertion of a nasogastric tube for the purpose of gastric suction to relieve distention in the upper gastrointestinal tract.
ursodiol is a drug that can dissolve gallstones and reduce the need for surgery.
Laparoscopic surgery is the usual method of treatment and is performed as soon as the patient is able to withstand it. In most cases the gallbladder is removed and a tube is inserted to establish drainage of bile that has been dammed up by the stone. (See also discussion of surgery at
gallbladder.) For those patients unable to withstand
cholecystectomy (gallbladder removal) but who still require drainage,
cholecystostomy is indicated.

Common anatomic locations of gallstones. From Malarkey and McMorrow, 2000.