Colonic intussusception in adults is extremely rare, accounting for about 5% of all cases of intussusception. The telescoping of a proximal segment in the lumen of the adjacent segment has a classic classical triad in the symptomatology of children: abdominal pain, bloody diarrhea and palpable abdominal mass. In the adult patient, the symptoms are almost absent, and rarely they consist of constipation, bloody stool, or a malignant pathology that accompanies intussusception, weight loss, and anemia. We present the case of a 86-year-old patient who underwent a surgical procedure for repairing a rectal prolapse; intraoperatively, we discovered a sigmoid intussusception for which we performed a segmentary sigmoidectomy, repairing the rectal prolapse by rectosacropexy with alloplastic mesh