LAUSR

A 42-year-old man with no prior medical history presented with perianal pain and pustular drainage over the course of 1 week. On physical examination, he had a perianal abscess with a draining sinus tract, but no abdominal tenderness to palpation. Laboratory tests showed severe iron deficiency anemia. As part of a workup for this, an upper gastrointestinal endoscopy was performed, which was unremarkable. Subsequently, a colonoscopy was performed, which revealed no mucosal inflammation but did show a large focal region of the mid-transverse colon, which spontaneously protruded and retracted (▶Video 1). To evaluate this further, a computed tomography (CT) scan was performed, which revealed a colocolonic intussusception of the transverse colon, without any focal neoplasm (▶Fig. 1). The patient’s perianal abscess improved on antibiotics without the development of any further symptoms and he was discharged home. Colocolonic intussusception is a rare finding and is usually associated with malignancy in adults, but can also occur spontaneously [1]. About 20% of such cases are transient or asymptomatic in adults and may not necessitate surgical intervention [2]. Abdominal CT can accurately diagnose intussusception in approximately 78% of patients; findings typically include a target-like or sausage-shaped mass with a layering effect [3, 4]. Endoscopy provides invaluable information through direct visualization in order to precisely determine the lead point, as demonstrated by this case.