Digestive tract duplications are uncommon congenital anomalies, encountered mostly in the first 3 months of life. Overall the rectum is the least common site of alimentary duplications. We represent a case of large cystic non-communicating duplication that manifested with constipation and profuse rectal bleeding. When diagnosis was established, surgery was planned and the cyst was enucleated completely. Histopathology examination confirmed the diagnosis.