We've had good results with a cleanse from Pro Star International called Pro Action. In spite of regular consumption of fruits and veggies, frequent exercise, weight close to normal, and general good health, irregularity (monthly) was experienced.
A day or two after beginning the cleanse capsules, regular bowel movements return. Cost is less than $.50 a day. Web site listed below has all ingredients and information.
Pro Action The Super Enzyme-Oxygen Colon Cleanse