Summary

We present a case of pyeloduodenal fistula in an 89-year-old woman with history of nephrolithiasis and recurrent urinary tract infection (UTI) who presented to the emergency department with back pain. CT revealed a malrotated right kidney with a large renal stone and possible fistulous connection between the second portion of the duodenum and the right renal collecting system. Technetium-99m scintigraphy confirmed presence of the fistula. The patient declined intervention and was discharged from the hospital with oral antibiotic suppressive therapy. The patient remained clinically stable at time of follow-up 3 months later. Spontaneous pyeloduodenal fistula is an aetiology of recurrent upper or lower UTIs or persistent bacteriuria though uncommonly recognised. Diagnosis may be achieved using several modalities, including technetium-99m scintigraphy. Nephrectomy and primary fistula closure has traditionally been the treatment of choice for this condition; however, conservative management is an option for patients with intact renal function.