the small pieces of coconut are acting to slow down the bowel flow rate. basically you are using the tiny pieces of coconut as a fiber in your diet. diet fiber is physically smaller than coconut chunks but the concept is the same, as the chunks themselves have fiber. The difference is that since the coconut pieces are larger, and if you have a stricture, there is a chance you could stop it up, i.e. have a blackage, while smaller fiber in metamucil, for example, might still pass, of course that depends on much and that you do not overdo it as well.. So yes a large amount of the coconut will pass undigested since coconut itself is made up of alot of fiber. This fiber helps feed the friendly bacteria and so the benefit is twofold. The food that follows should be healthy , as you are forcing the bowel to deal (slower) with whatever food follows with the fiber and you really want that to be good food since it will be present longer.