I have Crohn's disease and often have problems with blockage. There are several foods that you father should avoid. Nuts, Popcorn, chocolate, red meats, and fruits with the peel on them. All of these can cause blockage and or pain. When I am having a hard time, I steam vegetables, like carrots or squash. He can also eat potatoes, pasta's, eggs, peaches (without peels). Basically, mild soft foods. Drinking peppermint herbal teas may aid in digestion also. Good luck!