Young woman with long history of crampy abd pain, diarrhea, + relieved by defection, without red flag symptoms.

It's IBS

Tricyclics can be used for IBS; they help with pain and can help with diarrhea

Could also have used antispasmodics like dicyclomine and hyoscyamine for the pain

For diarrhea, can also use loperamide or other antidiarrheals

For constipation type IBS try fiber, osmotic laxatives, lubiprostone

IBS is a “functional” G.I. problem, which means that it is a diagnosis of exclusion (must rule out IBD, Celiac, etc). You may have enjoyed its recent popular appearance on television as a disturbing anthropomorphized walking bowel. Common symptoms include diarrhea, constipation, pain relieved by defecation, and flatulence, often subject to a degree of emotional valence. As such, like headaches, IBS symptoms can be improved by TCA therapy, such as nortriptyline.