NPO4, or sodium phosphate, is a chemical compound commonly used in various applications, including food processing and pharmaceuticals. It is a salt formed from the reaction of sodium hydroxide and phosphoric acid, and it plays a role in maintaining pH levels and acting as a buffering agent. In the medical field, NPO4 is often utilized in preparations for diagnostic imaging and as a laxative before certain procedures. It helps to cleanse the bowel by drawing water into the intestines, making it easier for healthcare providers to perform examinations or surgeries safely.