This kitten has not pooped as far as we know for it's whole life. It's about 3 weeks old, very skinny.. The vet did a q-tip check and there was fecal matter on it, so no congenital defect. His brother pooped, but then again his brother just passed away last night. This one is not pooping. Peeing, yes, but not pooping. I heard to try giving him olive oil and mashed pumpking.. What do you think?