PREPOPIK ((sodium picosulfate, magnesium oxide, and anhydrous citric acid), supplied as a powder, must be reconstituted with cold water right before its use. There are two dosing regimens, each requires two separate dosing times: The preferred method is the “Split Dose” method and consists of two separate doses: the first dose during the evening before the colonoscopy and the second dose the next day, during the morning prior to the colonoscopy. The alternative method is the “Day Before” method and consists of two separate doses: the first dose during the afternoon or early evening before the colonoscopy and the second dose 6 hours later during the evening before the colonoscopy). Additional fluids must be consumed after every dose in both dosing regimens. Instruct patients to consume only clear liquids (no solid food or milk) on the day before the colonoscopy up until 2 hours before the time of the colonoscopy. Instruct patients that if they experience severe bloating, distention, or abdominal pain following the first dose, delay the second dose until their symptoms resolve.

Sodium picosulfate was biotransformed by intestinal flora that produced a novel sulfotransferase (not sulfatase). The biotransformation was activated by adding phenolic compounds such as phenol, acetaminophen and flavonoids. The enzyme activity related to this biotransformation was the highest in the contents of the caecum region of the intestine. The enzyme activity was 3.0 umole/hr/g wet feces in humans and 0.75 in rats (pH 8.0). The optimal pH was 9.0. The sulfotransferase activity was assayed in reaction mixture consisting of 60 uL of 50 mM PNS (occasionally sodium picosulfate), tyramine and 0.2 ml of the enzyme solution. Sulfatase activity was measured under the assay conditions for he sulfotransferase acitivity without the addition of the acceptor tyramine.