Isolated ascending colon perforation from blunt trauma in an eleven-year-old adolescent: a case report

BACKGROUND: Colonic perforation from blunt abdominal trauma is rare in children and often presents a diagnostic challenge due to delayed or atypical symptoms. Handlebar injuries are a known cause of localized trauma, typically affecting the small bowel or pancreas; isolated colonic perforation is exceedingly rare. CASE PRESENTATION: An 11-year-old boy presented with right lower quadrant pain and anorexia two days after a bicycle fall where his abdomen struck the handlebar. He was initially assessed and discharged from another clinic. Upon representation, physical examination revealed a handlebar-shaped bruise over the right iliac fossa and abdominal rigidity. Contrast-enhanced CT demonstrated a defect in the medial wall of the proximal ascending colon with pericolonic inflammation and pneumoperitoneum. Exploratory laparotomy revealed a 1.5 cm perforation without gross contamination. A limited right hemicolectomy with stapled ileocolic anastomosis was performed. The postoperative course was uneventful except for a superficial wound infection managed conservatively. CONCLUSION: Isolated blunt colonic injury is rare (< 1% of blunt abdominal trauma) and is frequently diagnosed late, increasing morbidity. This case of an 11-year-old boy highlights that the distinctive “handlebar sign” bruise should raise immediate suspicion for hollow viscus injury, even after a benign initial assessment. Early CT imaging and prompt surgical intervention are essential to prevent serious complications. Any child with localized abdominal bruising after blunt trauma requires thorough evaluation and early imaging to exclude bowel injury, as timely management yields excellent outcomes.