SummaryAuthors report on a case of achrestic anemia with symptoms of intravascular hemolysis.The patient was a 49 years old man. He died when operated for intestinal obstruction.Post mortem examination showed on the distal part of the small bowel two sheathes of non inflammatory tissue resulting in thickening of the walls and narrowing of the bowel lumen.Authors discuss the possible relation between the anemia and the intestinal lesions. They suggest that the last are secondary to the anemia and, on the basis of microscopic observations, that they recognize an allergic origin.