Abstract
Experimentally induced oral Salmonella typhimurium infection in pigs resulted in a severe, prolonged enterocolitis with ulcerative proctitis a constant feature. Healed lesions were annular cicatricial ulcers in the part of the rectum affected with rectal strictures. Strictures indistinguishable from the naturally occurring lesion were produced by injecting chlorpromazine into the cranial hemorrhoidal artery of three pigs. Dye injected into the cranial hemorrhoidal artery perfused the entire rectum in normal pigs, but in pigs with either rectal stricture or salmonella proctitis the dye halted at the cranial margin of the transverse mucosal defect. The predilection of rectal stricture and its proposed precursor, salmonella ulcerative proctitis, for the middle third of the rectum was attributed to a normally precarious arterial supply which renders the rectum unusually susceptible to ischemic injury and decreases its reparative capacity.