This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition.
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Polyethylene Glycol 3350/Gatorade Colonoscopy Preparation
If the patient has kidney disease or severe heart or liver disease, the patient should NOT use this preparation.
The patient should plan to start this bowel cleansing preparation the day before the scheduled procedure. Plan to be near a bathroom from the time the preparation is started until the end of the evening. The patient’s bowels may begin to move in about thirty to sixty (30 to 60) minutes. Feelings of nausea and bloating are common and resolve with time. An A+D type ointment applied to the rectal area can help with any irritation in that area. The goal is for the patient’s stool to be clear or light yellow water.
Supplies:
- 2 bisacodyl tablets, which are available at any pharmacy. No prescription needed.
- Polyethylene glycol 3350 powder, which is available at any pharmacy. No prescription needed. Also sold under the name MiraLax.
- Choice A: Buy one (1) 238-gram bottle of polyethylene glycol 3350 powder
or
- Choice B: Buy two (2) 119-gram bottles of polyethylene glycol 3350 powder.
- Choice A: Buy one (1) 238-gram bottle of polyethylene glycol 3350 powder
- two (2) 32-ounce bottles of Gatorade (64 ounces total). It must be Gatorade. Do not substitute.
Note: The 255-gram bottle of generic polyethylene glycol 3350 powder (or GlycoLax) currently requires a prescription. Be sure to get the non-prescription polyethylene glycol 3350.
Optional Supplies:
- A+D type ointment for rectal irritation.
One day before the procedure, refer to the booklet titled “Colonoscopy: A Guide for Patients” for complete procedure information.
_____ Between 12 noon and 5 p.m. the day before the colonoscopy, take two (2) bisacodyl tablets by mouth with water. Do not crush or chew. Do not take within one (1) hour of taking an antacid. The first bowel movement should occur one to six (1 - 6) hours after taking the tablets.
____ After the first bowel movement, or by 6:00 p.m., for Choice A, mix one-half of a 238-gram (3/4 cup) or a 255-gram bottle of polyethylene glycol 3350 powder in 32 ounces of Gatorade. Drink this over one to two (1 - 2) hours. For Choice B, mix one (1) of the 119-gram bottles with 32 ounces of Gatorade. Drink this over one to two (1 to 2) hours.
_____ The second dose should be three to twelve (3 - 12) hours later, preferably the morning of your colonoscopy, although it should be at least 4 hours before the colonoscopy. The closer the second dose of the preparation is taken to the actual procedure, the better the preparation will be! Mix the remaining one-half bottle of polyethylene glycol 3350 powder in another 32 ounces of Gatorade or mix the second 119-gram bottle polyethylene glycol with 32 ounces of Gatorade. Drink this over one to two (1 - 2) hours.
Take other clear liquids between doses of laxative. If the patient drinks at least one (1) gallon of clear liquids during the evening, the quality of bowel cleansing will be improved. See the colonoscopy booklet for allowed liquids.
If the procedure is scheduled at 10:00 a.m. or later, take the first dose of the bowel prep the evening before the procedure, as described above. Take the second dose the morning of the procedure, starting at least 4 hours before the patient is scheduled to be at the procedure unit.
