Final answer:
Over 80 percent of pancreatitis cases in the U.S. are caused by gallstones or chronic alcohol use, which lead to inflammation of the pancreas.
Step-by-step explanation:
The cause of over 80 percent of pancreatitis cases in the United States is either gallstones or chronic alcohol use. Pancreatitis is an inflammation of the pancreas that can lead to serious health complications. Gallstones are small, pebble-like substances that can block the ducts of the pancreas, leading to inflammation. Chronic alcoholism can also damage the pancreas over time. These two factors are the primary culprits behind the majority of pancreatitis cases.