I like the suggestion I've been hearing from dietician's lately that you shop the perimeter of the grocery store rather than the aisles. The perimeter has the fresh meat, dairy, produce and usually the freshly baked items. The aisles have processed foods which tend to be high in fat with lots of chemicals. It's a very easy way to remind yourself what you should be eating
Having Crohn's Disease cleanses you pretty regularly but I don't recommend it! Colonoscopy prep is awful. Colonoscopies are easy peasy.