Colonic duplication is a rare congenital anomaly which presents as a diagnostic and therapeutic challenge. We report a 5-year-old boy with colonic duplication who required multiple hospital admissions, multiple diagnostic tests, and evaluation by various clinical specialists before the diagnosis was made intraoperatively. He was known to have left renal hypoplasia, low spinal abnormalities, hypoplasia of the left hemipelvis, and mild hypoplasia of the left lower limb, all of which were considered to be a variant of caudal regression syndrome.