Final answer:
Gallstones and chronic alcohol use are the two most common causes of acute pancreatitis in the US.
Step-by-step explanation:
The two most common causes of acute pancreatitis in the United States are gallstones and chronic alcohol use. Gallstones can block the pancreatic duct, leading to inflammation, while chronic alcohol use can cause damage to the pancreas and trigger inflammation. Other possible causes of acute pancreatitis include infections, genetic factors, certain medications, and high levels of triglycerides in the blood.