Phospho-soda Oral Laxative Preparations
If you have severe heart or liver disease or any kidney disease, you should NOT use a phospho-soda laxative preparation. Also, if you take medicines for blood pressure or heart disease (ACE inhibitors or angiotensin receptor blockers), diuretics (water pills) or certain arthritis medicines (NSAIDs) you should not use this type of preparation unless instructed to do so by your health care provider.
There are two types of oral phospho-soda laxative, a liquid which is available over the counter and prescription tablets. With either of these preparations, you will start the day before your colonoscopy and need to plan on being near a bathroom for the rest of the evening. Your bowels may begin to move in about 30-60 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. The goal is for your stool to be clear or light yellow water.
Phospho-soda Oral Saline Laxative
_____ Between 12 p.m. and 6 p.m. the day before your colonoscopy, mix 1½ ounces of Fleet Phospho-Soda Oral Saline Laxative with 4 ounces of water or soda and drink immediately. You may be able to drink the solution faster by using a straw. Have another clear liquid immediately available to “wash away” the laxative taste.
_____ The second dose should be 10-16 hours later, and at least 4 hours before the colonoscopy. Mix 1½ ounces of Fleet Phospho-Soda Oral Saline Laxative with 4 ounces of water or soda and drink immediately.
You should take other clear liquids between doses of laxative. Drinking at least a gallon of clear liquids during the evening will improve the quality of bowel cleansing and prevent dehydration. See the colonoscopy instructions for allowed liquids.
If your procedure is scheduled at 11 a.m. or later, wait and take the second dose the morning of your procedure, starting at least 4 hours before you need to be at the procedure unit.
Phospho-soda tablets (OsmoPrep)
You will take a total of 32 tablets, divided into 2 sets of tablets, beginning the day before your colonoscopy. You will need a prescription for OsmoPrep.
_____ Begin taking the first set of 20 tablets between 12 p.m.and 6 p.m.. Take a dose of 4 tablets every 15 minutes. (For example, 4 tablets at 4 p.m., 4 at 4:15 p.m., 4 at 4:30 p.m., etc) It will take 1 hour to take the 20 tablets. Take each dose of 4 tablets with at least 8 ounces of clear liquid.
_____ The second set of 12 tablets should be taken 10-16 hours later, and at least 4 hours before the colonoscopy. Again, take a dose of 4 tablets every 15 minutes. It will take 30 minutes to take the second set of 12 tablets. Take each dose of 4 tablets with at least 8 ounces of clear liquid.
You should take other clear liquids between doses of laxative. Drinking at least a gallon of clear liquids during the evening will improve the quality of bowel cleansing and prevent dehydration. See the colonoscopy instructions for allowed liquids.
If your procedure is scheduled at 11 a.m. or later, wait and take the second set of 12 tablets the morning of your procedure, starting at least 4 hours before you need to be at the procedure unit.
Information provided by UMHS Medical Procedures Unit staff MPU/MPC, April 2008
