S3770 When Bowel Telescopes: A Hidden Adenocarcinoma Masquerading as Post-Cleanse Complications

Introduction: Adult colocolonic intussusception is rare, comprising <5% of all intussusceptions, with 80% caused by malignant lesions. This case demonstrates an unusual presentation of colorectal adenocarcinoma manifesting as intussusception following herbal colon cleanse use, highlighting diagnostic challenges in adults with nonspecific abdominal symptoms. Case Description/Methods: A 67-year-old man with history of prostate cancer s/p radiation presented with 1 month history of abdominal pain, bloating, and diarrhea following use of herbal colon cleanse. Initial symptoms included bloody diarrhea that resolved, but persistent lower abdominal pain continued. Physical exam revealed bilateral lower quadrant tenderness. Computed tomography abdomen/pelvis demonstrated colocolonic intussusception at splenic flexure involving distal transverse colon to descending colon with wall thickening. Colonoscopy was attempted but terminated at sigmoid colon due to complete obstruction; biopsy showed inflammatory debris. Due to irreducible intussusception, patient underwent laparoscopic left colectomy with colostomy creation. Surgical pathology revealed 4 cm moderately-differentiated invasive adenocarcinoma extending through muscularis propria into pericolonic tissue, with negative margins and lymph nodes (0/9). Patient had uncomplicated recovery with return of bowel function. Discussion: This case illustrates adult colocolonic intussusception as a rare presentation of colorectal malignancy. The temporal association with herbal cleanse use may represent coincidental timing or potential triggering factor. Key learning points include: high index of suspicion for underlying malignancy in adult intussusception, critical role of colonoscopy for tissue diagnosis despite technical limitations with obstructing lesions, and multidisciplinary approach combining endoscopic evaluation with surgical management.