List of products in the National Drug Code with proprietary name . See also Warning section. Plecanatide is used to treat certain types of bowel problems (chronic idiopathic constipation, irritable bowel syndrome with constipation). It works by increasing fluid in your intestines and helping speed up movement of food through the gut. Plecanatide may improve stool texture and lessen symptoms such as straining and feelings of incomplete bowel movements. This medication must not be used in children younger than 6 years because of the risk of serious side effects.