As far as I'm aware whether or not you have diarrhea after your ileostomy reversal goes by a case by case basis because from what I've read it depends on how much of the colon has been removed since that's where a large portion of the fluids are absorbed or it could also depend on the amount of good flora in your colon being too low. It's common to have diarrhea after a ileostomy reversal but for many people things do go back to normal. For some people the diarrhea lasts for weeks and others have mentioned months to years yet some people have said that its never gone back to normal. It's been a while since I've seen this type of issue mentioned on the forum but I have seen it in the past so I know you're not alone at least. Have you tried medications like Lomotil to help with the diarrhea?