A diet that incorporates foods high in fiber, such as wheat bran, helps prevent constipation and may help to reduce occurrence of rectal prolapse. However, be careful to add fiber to your diet slowly. It takes a while for your digestive system to adapt to increased amounts of fiber.
Here are some simple ways to add fiber to your diet:
Also, drink plenty of water because it helps keep stools soft.
WebMD Medical Reference from Healthwise