Exocrine pancreatic insufficiency (EPI) causes problems in how you digest food. Your pancreas doesn't make enough of the enzymes that your body needs to break down and absorb nutrients. Enzymes speed up chemical reactions in your body. The enzymes made by your pancreas move into your small intestine, where they help break down the food you eat. When you have EPI, you don't get the nutrition you need because your body can't absorb fats and some vitamins and minerals from foods. You might lose weight or have pain in your belly.