RAP is if you have at least 3 stomachaches over 3 months, and they’re severe enough to keep you from doing everyday activities. They can be caused by clear medical problems, such as heartburn or anxiety. But many adults and kids have RAP without an obvious cause. Then, it’s called functional abdominal pain. Doctors don’t know what causes it, but things like stress, personality, and genes may play a role. Another idea is that the nerves in the digestive tract are more sensitive than they are for most people.