lelet- Phsopho soda is is available at most pharmacies, and is used to prepare the intestines for examination like colonoscopy or barium
enema. It is a strong laxative and you will feel the effects for several hours, so don't leave the house! The taste is kind of weird - a bit oily. I have a tough time getting it down even when mixed with something I like, and still have to just hold my nose and gulp it.