Eluxadoline dihydrochloride is primarily used in the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults. It works by activating opioid receptors in the gut, which helps to reduce bowel movements and alleviate diarrhea. Additionally, it blocks certain nerve signals that can cause pain and discomfort in the digestive tract. This dual action makes it effective in managing both the frequency of bowel movements and the abdominal pain associated with IBS-D. It is typically prescribed when other treatments have not provided sufficient relief, offering patients a way to improve their quality of life by controlling symptoms more effectively.