Diphenoxylate + atropine is used to treat diarrhea. It helps to decrease the number and frequency of bowel movements. Diphenoxylate works by slowing the movement of the intestines. Diphenoxylate is similar to narcotic pain relievers, but it acts mainly to slow the gut. Atropine belongs to a class of drugs known as anticholinergics, which help to dry up body fluids and also slow gut movement.