Suggest Treatment For Abdominal Pain And Loose Stool With Blood In It

My husband is experiencing bowel changes, but just recently told me it has been going on for a while. Loose stools, blood, pain in his stomach, groin, gas and fatigue. He is a very health minded man. He swims 4 times a week (80 laps) and bikes to work every day. He told me he has falled twice at work related to having bowel discomfort.