I've had both done multiple times, and I've never ever prepped with a enema through my ostomy. I've only prepped with a liquid like milk of magnesium that you drink. You should not have to be asking your pharmacist, the doctor that ordered your tests should be answering your questions. I would suggest you call the dr. and remind them you have an ostomy (I know, dumb right?) but often they schedule the tests as a routine type thing and forget to take note of such thing's. I would also mention to the doctor's that it's their job to know how to prep your body for this type of procedure. If I were you I'd outright ask them if they've preformed this procedure on someone with an ostomy before. Because first of all, they prescribed you an enema when you have an ostomy and second of all to suggest the pharmacy know how to give medical advice about what you should or shouldn't be taking for a procedure is ridiculous. It's not just a medication it's part of a prep for a procedure. I would suggest you schedule the procedure with an actual gastrointestinal doctor's office because you should not be left with these kinds of questions before having this procedure done. Sorry to seem harsh lol but you are your best advocate, don't allow them to leave you with unanswered questions.