US attorney General John Ashcroft has been hospitalized in an intensive care unit for a severe case of gallstone pancreatitis, his chief spokesman said Friday. Ashcroft, a 61-year-old former Missouri senator who has been free of health problems, canceled an appearance Thursday afternoon at which he was to have announced verdicts in a terrorism case. Justice Department spokesman Mark Corallo said the attorney general initially believed he had a stomach flu. "He went home and when the condition worsened, he was visited by White House physician Daniel Parks, who advised that he go to the emergency room," Corallo said. He said Ashcroft was taken Thursday night to the George Washington University Hospital for evaluation. "After a full medical work up in the emergency room, it was determined that he was suffering from a severe case of gallstone pancreatitis," Corallo said. "He was admitted to intensive care for careful monitoring and is being treated with antibiotics." Corallo said he expects Ashcroft will spend a couple of days in the hospital. Pancreatitis is an inflammation of the pancreas usually caused by excessive alcohol use or, a gallstone that blocks the passage leading from the pancreas to the beginning of the small intestine. It also may be caused by infection, injury or certain medications. Symptoms include sudden, severe abdominal pain, loss of appetite, nausea, vomiting and fever. **PHOTO CAPTION*** John Ashcroft speaks during a press conference in New York, Tuesday March 2, 2004. (AP)