a week or two depending on then i end up in the hospital where i get a feeding tube or i'm given nutrients intravenously. that is. when things get bad stephanie suffers from severe stomach ache diarrhea and fatigue but now that she is receiving treatment here at the hospital flare ups occur less frequently scientists still aren't exactly sure what causes crohn's disease since in effect there are four major factors at work first of all where you come from what country and what you eat then there are genetic factors. we also believe that the composition of bacteria viruses and parasites in your gut plays a major role. he said last but not least there's your immune system it appears the immune system can overreact to the contents of the gut. and there may be some