Rare causes of abdominal pain: a primer for the admitting general surgeon

The broad uptake of the acute surgical unit (ASU) model of surgical care in Australia has resulted in general surgeons becoming increasingly involved in the management of patients with acute abdominal pain (AAP), some of whom will be labelled as having non-specific abdominal pain (NSAP) (Kinnear N, Jolly S, Herath M, et al. The acute surgical unit: An updated systematic review and meta-analysis. review. Int. J. Surg. 2021;94:106109; Lehane CW, Jootun RN, Bennett M, Wong S, Truskett P. Does an acute care surgical model improve the management and outcome of acute cholecystitis? ANZ J. Surg. 2010;80:438-42). NSAP patients lack a clear diagnosis of surgical pathology based on standard clinical, laboratory and imaging work-up, although they may require ASU admission for pain control and assessment. This article provides a review of uncommon conditions, presenting as AAP, that could possibly be mis-labelled as NSAP, with a focus on aspects of the presentation that may aid diagnosis and management including specific demographic features, clinical findings, key investigations and initial treatment priorities for ASU clinicians. Ultimately, most of the conditions discussed will not require surgical intervention, however, they require a diagnosis to be made and initial treatment planning before on-referral to the appropriate specialty. For the on-call general surgeon, some knowledge of these conditions and an index of suspicion are invaluable for the prompt diagnosis and efficient management of these patients.