Summary A 4‐month‐old colt foal was admitted to the hospital with a history of acute stranguria and colic signs. On presentation, he was tachycardic, tachypnoeic and pyrexic. Blood work showed marked leucocytosis and severe azotaemia. Ultrasound examination of the abdomen revealed a reduced bladder lumen and a large volume of free peritoneal fluid. Abdominocentesis confirmed uroperitoneum. The foal underwent a general anaesthetic to repair the bladder. Unfortunately, the following day, the uroperitoneum recurred, so a revision surgery was performed. The bladder wall was repaired and a large impaction of the terminal small colon and rectum was diagnosed at this point. Rectal examination post‐operatively revealed a spherical mass compressing the dorsal aspect of the rectum, which reduced its diameter by approximately 75%. Ultrasound examination, cytology and culture of a fine‐needle aspirate of the mass revealed it to be a perirectal abscess, and this was drained per rectum and lavaged several times. The foal recovered well, regained the ability to micturate and remained healthy at subsequent post‐operative checks. It is suspected that the perirectal abscess led to overdistention and subsequent rupture of the bladder.