1. 1. Ten cases of intussusception have been seen at the Peter Bent Brigham Hospital during the period 1913 to 1968. 2. 2. Six of the patients had a chronic history of vague abdominal pain; only four cases presented as acute abdominal emergency conditions. 3. 3. In eight of the cases an underlying cause for intussusception was found; the various causes were duodenal carcinoma, three submucous lipomas of the small bowel (two cases were previously reported from this institution by Botsford and Newton [6]), an invaginated Meckel's diverticulum, and two carcinomas of the rectosigmoid. Table I Intussusception in Adults (1913–1968) Patient Age (yr.) and Sex History Physical Exam Laboratory Data Operation Results A. G. 75, F Chronic Negative Benzidine-positive stool; upper gastrointestinal series showed intussusception of third portion of duodenum into fourth portion Reduction of duodenal intussusception; resection of distal duodenum and proximal jejunum for adenocarcinoma of duodenum Died 1 yr. post-operatively of renal cell carcinoma S. C. 48,F Acute 5 by 15 cm. Lower abdominal mass Benzidine-negative stool; white blood cell count 22,700 per mm 3. Resection of 3.5 ft. of gangrenous distal ileum for an ileoileal intussusception secondary to submucous lipoma Benign post-operative course H. F. 69,F Acute Right upper quadrant mass Benzidine-negative stool; white blood cell count 6,900 per mm 3. Reduction of retrograde jejunal intussusception Benign post-operative course W. F. 39,M Chronic Right upper quadrant tenderness Benzidine-positive Benzidine-positive stool; barium enema demonstrated an ileocolic intussusception Right colectomy for ileocolic intussusception secondary to an invaginated Meckel's diverticulum Benign post-operative course F.M. 48,F Chronic Negative Benzidine-positive stool; small bowel series demonstrated jejunal intussusception Reduction of jejunal intussusception secondary to adenomatous polyp and resection of small bowel containing polyp Benign post-operative course J. M. 62,M Chronic Rectal mass Benzidine-positive stool Abdominoperineal resection for carcinoma of rectum with intussusception Benign post-operative course V.M. 22,F Chronic Negative Benzidine-negative stool Resection of small bowel for jejunoileal intussusception secondary to submucous lipoma Benign post-operative course J. M. 13,M Acute Tender left lower quadrant mass Benzidine-positive stool; white blood cell count 11,000 per mm 3. Mikulicz colostomy for sigmoid intussusception; no underlying cause found Benign post-operative course M. C. 63, F Acute Right lower quadrant mass Stool benzidine test not done; white blood cell count 15,300 per mm 3. No operation; severe cardiac disease; necropsy, ileocolic intussusception secondary to submucous lipomas and fibromas of small bowel; gangrene from ascending colon to sigmoid Died on fifth hospital day G. L. 53,M Chronic Tender mass in left lower quadrant Stool benzidine test not done Sigmoid resection for intussusception secondary to adenocarcinoma Benign post-operative course 4. 4. Eight of the ten patients required bowel resection. 5. 5. Eight cases experienced an uncomplicated postoperative course with no subsequent difficulties; one patient died one year postoperatively from metastatic renal cell carcinoma and one patient with severe cardiac disease died on the fifth hospital day with no surgery having been undertaken.