Intermittent right iliac fossa pain: does ultrasound have a role to play? A Srikanthan, J Pilcher Abstract Background Acute right iliac fossa (RIF) pain is a very common clinical presentation, for which the differential diagnoses, biochemical and imaging evaluation is well described. Intermittent or chronic RIF pain on the other hand is a more contentious entity and correct diagnosis of the underlying pathology often takes a more protracted course. Ultrasound can potentially play a key role in making the diagnosis, particularly as clinical and biochemical findings are often unhelpful, or in younger patients where the use of ionising radiation is preferably avoided. Case presentation We present the case of a young female patient with intermittent RIF pain, lasting for a week at a time, being asymptomatic between episodes. Initial investigations only found a mildly elevated faecal calprotectin. Ultrasound examination revealed an appendicolith within, what was initially interpreted as, a chronically inflamed appendix. Subsequent resection revealed a carcinoid tumour within the distal appendix. The ultrasound appearances, with reference to histological images, of this relatively uncommon tumour will be presented. The subsequent discussion will focus on other pathologies to consider in the evaluation of the patient with recurrent / intermittent RIF pain: including Crohn’s disease, caecal diverticulum, endometriosis, and musculoskeletal pathologies. The ultrasound findings in a number of these conditions will be outlined and illustrated. Conclusion Ultrasound can be extremely useful in the evaluation of patients who present with intermittent or chronic right iliac pain and can unveil a number of diagnoses not often considered on initial presentation.