RESUMEN
A young male patient presented with right lower abdominal pain and fever. He had tenderness in the right lumbar region, with no palpable lump. Subsequently he developed a tender fluctuant lump in the right loin. Abdominal ultrasonography showed heterogenous collection in the right lumber region near the posterior abdominal wall. Making a diagnosis of right-sided perinephric abscess, drainage was done. The patient was discharged. Eight months after his discharge, he developed fever and painful swelling in the previous operation site followed by spontaneous discharge of pus. Sinogram showed the contrast passed through the sinus tract into the large bowel and into the terminal ileum. Laparotomy, fistula tract was found communicating with the appendix. Appendicectomy and curettage of the fistula tract was followed by complete cure.