Two of the five Zelnorm patients had known gallstone disease before taking the drug.

FORBES: Crisis in the Cabinet

Seeing a patient who has had uncomplicated, first-time gallstone pain requires some judgment.

NEWYORKER: The Cost Conundrum

He was hospitalized in early December and a week later underwent gallstone surgery.

CNN: Mandela released from hospital

Ashcroft, 61, was discharged shortly after noon from George Washington University Hospital, where he was diagnosed with severe gallstone pancreatitis and operated upon.

CNN: Ashcroft discharged from hospital

In January, Mandela completed his recovery from a lung infection and gallstone surgery and gradually returned to his normal routine, officials said at the time.

CNN: Nelson Mandela hospitalized for routine checkup

Ashcroft entered the hospital last Thursday night with acute gallstone pancreatitis.

CNN: Ashcroft remains in intensive care

Gallstone pancreatitis is a condition in which a gallstone blocks a duct of the pancreas, a gland that produces enzymes that aid in the digestion of food.

CNN: Ashcroft remains in intensive care

Mandela, who has not appeared in public since 2010, has been recovering from a lung infection and gallstone surgery while at his home in Houghton, a suburb of Johannesburg.

CNN: Mandela released from hospital

The most common cause of pancreatitis is gallstone obstruction of the duct leading from the pancreas to the small bowel, causing the fluids to back up into the pancreas.

CNN: What could be causing my pancreatitis?