pumpkin adds fiber. fiber absorbs water. absorbing water does 2 things: in the case of constipation, absorbing water creates looser stools, therefore making stools easier to pass, or firming stools up...whichever is needed. Pumpkin is used by holistic vets to treat blockages and diarrhea. It is a natural way to keep ferrets from developing furballs. This has been discussed on other forums. Louise [Posted in FML 6166]