Apple Inc Chief Executive Officer Steve Jobs could be facing surgery to remove his pancreas, doctors say.

Jobs said on Wednesday he's taking a five-month leave of absence after discovering that his health problems are "more complex" than he thought last week.

Jobs had a procedure similar to a Whipple operation, which involves removing parts of the pancreas, bile duct and small intestine, after he was diagnosed with a rare type of pancreatic cancer in 2004. A potential side effect of this procedure is that the organ has to be removed to prevent pancreatic leak, and the patient has to be kept alive with insulin to regulate blood sugar, said Robert Thomas, head of surgery at the Peter MacCallum Cancer Centre in Melbourne.