Circumferential seromuscular stripping of the sigmoid colon with denudation of the mucosal tube over a length of 4 to 10 cm has been observed in four patients after blunt abdominal trauma. Three of the patients had been driving a motor car, with two of them wearing safety belts. One patient was injured when he was caught between steel bars at work. In two cases the sigmoid lesion was associated with a tear in the mesoileum, leading to ischemic bowel necrosis in one. In one patient the lesion was found 5 days after the accident when he presented the symptoms of diffuse peritonitis caused by secondary perforation of the denuded mucosal tube. Treatment consisted in resection, anastomosis and proximal colostomy in two, and resection with end colostomy and distal mucous fistula in the remaining two cases.--As long as perforation of the denuded mucosa has not occurred, symptoms may be minimal. Liberal use of peritoneal lavage in polytraumatized patients is therefore important in order to minimize the likelihood of overlooking this type of bowel lesion.