This is a very tricky and challenging case where a 75-year-old man presented with the complaint of pain in the left lower pelvic region which was dull aching, non-radiating, and progressively increasing in intensity for the past four months. The patient also complained of the passage of stools per urine for the past few months. The patient gave a history of prior urological surgery at another health center and he neglected the follow-up care in his own words. On per rectal examination, the anal tone was normal, the lumen was collapsed and fecal staining was present. Routine blood investigations showed anemia and mildly elevated renal function.

A computed tomography (CT) without contrast then with intravenous, and cystography contrast was done which revealed the findings mentioned above with the initial diagnosis of missed towel (gossypiboma formation) complicated by recto-vesical fistula.

This initial diagnosis by the radiologist might have many medicolegal consequences including mental agony, humiliation, and huge monetary compensation on the part of the surgeon and increased morbidity, mortality, and financial loss on the part of the patient.

So, a second radiological opinion was a must in this case who take an action and contacted the surgeon who performed the operation many years ago, he denied any laparotomy was done and he claimed the operation was pyelolithotomy with left ureteric stent placement, yet the patient did not come back for follow up and removal of the stent.

On examination, the abdomen was free and no evidence of any surgical scar.

Secondly, the lesion is assumed to be at retroperitoneal space with its cavity communicating between two retroperitoneal viscous organs aspects.

Finally, there is a deformed left renal collecting system and ureter that might be related to a forgotten stent with inflammation, ureteric perforation, and migration forming foreign body reaction with its complication of transmural spread.

So the final diagnosis was forgotten (neglected) ureteric stent with migration and foreign body reaction complicated by rectovesical fistula.