Intestinal malrotation and duplication of the inferior vena cava are rarely diagnosed in adult patients; however, incidence is likely underestimated as they are usually asymptomatic. These congenital malformations have been previously reported in the same patient twice but never with colonic obstruction or ischaemia. A 25-year-old female presented with nausea, vomiting, obstipation, and abdominal pain, and on computed tomography of the abdomen and pelvis was diagnosed with a caecal volvulus and pneumatosis coli associated with intestinal malrotation requiring emergency right hemicolectomy. Incidentally, the patient was noted to have duplication of the inferior vena cava, azygos continuation of the inferior vena cava, and splenic fragmentation. This constellation of symptoms has not been reported in the literature previously. The pattern of malformations follows that of polysplenia syndrome. Although rare, awareness of these malformations can be useful to clinicians.