Syphilitic proctitis.

Two adult male homosexuals with syphilitic proctitis and without any detectable anal lesions are reported. There was no history or evidence of an external primary chancre in either patient. Of note, one had extensive rectal involvement of the first 20 cm and the other had multiple sites involved. One patient developed severe rectal bleeding following biopsy and a Jarisch-Herxheimer reaction after the first penicillin injection. Salient features of the literature are reviewed and discussed.