I took milk of magnesia (magnesium hydroxide) 6 hours ago to start colonoscopy prep, and it hasn't worked yet. i have not been constipated. what's wrong?

MOM for bowel prep?: Our gastroenterologist do not recommend Milk of Magnesia (MOM) as a bowel prep. Most have patients use Miralax (polyethylene glycol) (polyethelene glycol) because it is highly effective and more palatable than Go-Lytely, followed by Dulcolax (bisacodyl) tablets. U should have specific instructions from your GI doctor regarding what to take and when for bowel prep. Follow their instructions and call them if no effect.

Not enough: MOM is only used for constipation and is inadequate as a preparation for colonoscopy. You may have been told to take Magnesium Citrate but even this is not usually enough. Call your doctor's office for their recommendation ASAP.