Alimentary tract duplications are uncommon congenital anomalies that are often detected in the first decade of life. However, a smaller number of cases may remain unsuspected until adulthood. These anomalies are most common in the ileum and usually present at the bowel’s mesenteric border. These can also occur anywhere in the digestive tract. This article reports a case of a 74‑year‑old male with intestinal duplication arising from the antimesenteric border of the transverse colon, who clinically presented as sigmoid volvulus.