I think that laxatives just don't have any nutritional value and irritates the body in some way to make you poop. Ask yonkers he might know just a little bit more.
People do all kinds of crazy things for weight loss from bulimia to self inserting tape worms. Exercise really is crucial to losing weight and shaping your body. Hell even if you're not eating properly you can still stay relatively healthy if you workout. Think calories in and calories out.