A 21-year-old woman presented to the accident and emergency department with a 2-day history of lower abdominal pain. Her lips had the stigma of melanosis. Previously, she had received a diagnosis of Peutz-Jeghers syndrome, although no polyps had been detected in small and large bowel barium studies performed approximately 8 years before. Clinically, the patient had mild deep lower abdominal tenderness, and a mass was palpable in the suprapubic region. Urgent ultrasound showed ileoileal intussusception and small polyps in the lumen of the small bowel. At laparotomy, ileoileal intussusception was confirmed. It was not possible to reduce it because of nonviable small bowel, so 20 cm of the ileum, including the intussusception, was excised. After this, intraoperative enteroscopy was performed, showing further polyps in the small bowel distal and proximal to the intussusception, which were excised locally. Only a few reports in the literature describe ultrasound used to diagnose to condition. Intraoperative enteroscopy has been recommended as the treatment of choice because it allows identification of polyps that previously would have been missed.