Coloprep contains the active substances sodium dihydrogen phosphate monohydrate and disodium phosphate anhydrous which belong to a group of medicines that are described as purgatives (very strong laxatives). They are used to clean the bowel by causing large amounts of water to be drawn into the bowel resulting in diarrhoea. Coloprep is used for cleansing the bowel before certain diagnostic procedures such as colonoscopy. Coloprep is indicated in adults over the age of 18 years.