Call us today: 1 (210) 615-8308

8550 Datapoint Dr. Suite 200, San Antonio, TX

Gastroenterology Clinic of San Antonio

Osmoprep Colonoscopy Prep

Osmoprep tablets from the pharmacy (prescription)
Small box of dulcolax tablets (no prescription needed)
6 pack of 12oz cans of ginger ale


Follow the Colonoscopy Diet Instructions available here. This is very important and will help assure a clean prep and thorough exam. You will begin a liquid diet 24 hours before your scheduled procedure time.

Part 1. At about 6pm the day before your procedure take 4 tablets of the Osmoprep with 8oz of water every 15 minutes for a total of 20 tablets. After completing this drink a can of ginger ale. Take 2 of the dulcolax tablets at bedtime. It is very important that you drink at least 72oz of clear liquids during this bowel prep to reduce the risk of dehydration. You can continue to drink clear liquids until you go to bed.

Part 2. 10 hours before your scheduled procedure take 4 tablets of Osmoprep with 8oz of water every 15 minutes for a total of 12 tablets. After completing this drink a can of ginger ale. You can drink clear liquids of your choice up to 8 hours before your procedure but must finish all bowel prep and oral intake by 8 hours before your procedure.

If your procedure is scheduled for real early in the morning (6-8am) you may find it more convenient to just take the whole prep the day before instead of trying to split it into two doses. Start Part 1 at noon the day before and Part 2 at 10pm. However, if you can spit it as above it does work better.


Arrive at the endoscopy center one hour prior to your appointment with ONLY your driver’s license, insurance card and someone to drive you home. You will NOT be allowed to drive yourself home due to the sedation. You must bring your friend or relative with you to your appointment. You ARE NOT allowed to go home by taxi or BUS. If this is not followed then your procedure will be canceled and rescheduled and could be subjected to a fee. All personal items need to remain at home, you will not need your purse or wallet or jewelry during your colonoscopy.

The endoscopy center will be calling you to get medical history from you over the phone. The center is not in the same office as your doctor, so please be aware that the medical staff for the endoscopy center may call you.

Please let us know if you have any questions- we want your experience to be as safe as possible.

** There have been rare reports of kidney damage when using this type of colon prep in patients on certain blood pressure medications and non-steroidal anti-inflammatory medications. The risk is reduced if you drink a lot of fluids and stay hydrated. If you wish to switch to a different prep due to this risk let us know.

As Recognized in:

  • Super Doctors
  • Super Doctors
  • Top Gastroenterologists
  • Top Doctors
  • Top Doctors
  • Top Doctors
  • San Antonio Top Doctors