What happened, in summary

An 80-year-old independent man was admitted after a fall and was found to be feverish and unwell. He had been treated successfully for prostate cancer with brachytherapy 12 years earlier. A urinary catheter drained only small amounts of dark, foul-smelling fluid, and the scrotum and lower abdomen became swollen with gas under the skin. The findings initially raised concern for Fournier’s gangrene.

During cystoscopy, the instrument repeatedly entered the rectum through a fistula running between the rectum and prostate. A long-term suprapubic catheter was placed, and surgeons created a loop colostomy to divert stool away from the fistula. He required several weeks of intravenous antibiotics and antifungal treatment. When a large scrotal abscess developed, it was surgically drained and managed with daily dressings, after which the infection settled.

The fistula was attributed to newly diagnosed rectal adenocarcinoma. The colorectal team concluded that curative treatment was not possible. After discussing the options, he was referred to palliative care and discharged home with support. At the time the case was written, he remained relatively well. The earlier prostate brachytherapy was kept separate from the rectal-cancer treatment pathway because a causal relationship was only proposed, not established.