Biliary-type pain from sphincter of Oddi dysfunction is not uncommon after cholecystectomy. An increased basal pressure of sphincter of Oddi manometry establishes the diagnosis and treatment is usually by endoscopic sphincterotomy. Both procedures carry a significant complication rate. A few patients with elevated sphincter pressure do not respond to therapy; the source of their pain may be elsewhere. This case report describes the use of intrasphincteric botulinum toxin injection for the diagnosis of sphincter of Oddi dysfunction in a patient after repeated attempts at manometry had failed. This may provide a safe and easy method of determining whether sphincter of Oddi dysfunction may be the cause of biliary pain in post/ cholecystectomy patients and help select patients who would benefit from subsequent sphincter ablation, without the risks of sphincter of Oddi manometry. Prospective studies are first needed.