Nearly 1 million new cases of gallstone disease were diagnosed in 1987, making it one of the more common problems in clinical medicine, according to Dr. Gerald Salen.

Salen, professor of medicine at the University of Medicine and Dentistry of New Jersey, says one in 10 Americans, totaling close to 25 million, suffers from gallbladder disorders."About half of the cases diagnosed were asymptomatic and may remain untreated," he said. "Almost 500,000 other cases were treated surgically, about the same number as in 1986."

Salen said gallstones are more common in women but develop more frequently with increasing age in both sexes.