Irritable bowel syndrome or endometriosis, or both?

Both irritable bowel syndrome and endometriosis are common conditions, although symptomatic gastrointestinal endometriosis is extremely rare. We report the case of a patient initially thought to have irritable bowel syndrome, in whom the diagnosis of endometriosis only became clear following a laparotomy for small bowel obstruction. This case highlights the need to question the diagnosis in patients with irritable bowel syndrome when there is any uncertainty, and also to appreciate that other pathology can arise, even when the diagnosis is secure.