Presence of gallstones in the gallbladder may lead to acute cholecystitis - an inflammatory condition, wich is characterized by retention of bile in the gallbladder and often secondary infection by intestinal microorganisms. Presence of gallstones may cause obstruction of the bile ducts, which can lead to serious conditions such as ascending cholangitis or pancreatitis. Gallstones can vary in shape and shape size as small as a sand grain to as large as a golf ball. The gallbladder can contain a single stone or many smaller ones. There can be no symptomps for years or there can be intense pain in the upper-right side of the abdomen.