Traumatic Abdominal Wall Hernia With Sigmoid Colon Transection Following Bicycle Handlebar Injury: A Rare Case Report.

Traumatic abdominal wall hernia may occur when a focal blunt force from a bicycle handlebar transmits substantial energy to the abdominal wall and viscera despite minimal external injury. This injury creates a diagnostic challenge, as early clinical findings can be subtle while serious intra‑abdominal injury evolves. We report a case of a 45‑year‑old man who presented with delayed, progressive abdominal pain after low‑velocity handlebar trauma. An early contrast‑enhanced CT was decisive in identifying a large abdominal wall defect with bowel herniation, free air, and suspected colonic perforation, prompting urgent surgical intervention. Exploratory laparotomy revealed near‑complete sigmoid colon transection with fecal contamination, requiring Hartmann's procedure and abdominal wall repair. This case underscores that handlebar‑related abdominal trauma should lower the threshold for cross‑sectional imaging and early operative management, as timely intervention is critical to prevent missed hollow‑viscus injury and associated morbidity.