To help clean out your bowels for the procedure, your doctor has prescribed Magnesium Citrate. This is a laxative that can be bought over the counter at most pharmacies.
The day before your procedure, you should only have clear liquids to drink or eat in the morning. This includes: black coffee or tea, bouillon, water, apple, grape, or cranberry juice, soda pop, Gatorade, hard candy such as Life Savers or lemon drops and Jello. Make sure not to eat or drink anything with blue or red dye. The dye makes it more difficult to see the inside lining of the colon. You should also not have any dairy products like milk, ice cream, or cream soup.
You should begin taking the medicine at 4 pm. Your instructions will tell you how much to take at that time. You will take another dose at 7 pm. Because the medicine has a bitter taste, many patients say that drinking root beer helps this go away.
In between 4 and 7 o'clock, you will need to drink at least 3 to 6, 8 ounce glasses of clear liquid. Try to drink more if possible.
The Magnesium Citrate works by taking extra water from your body and moving it to the colon. This causes the feces in your colon to break up and will start diarrhea. It can take up to 4 hours for the diarrhea to start. So that you do not become dehydrated, it is very important that you drink as much liquid as possible throughout the day.
After you have taken both doses of the Magnesium citrate, you can still have clear liquids until 4 hours before your colonoscopy.