Colitis and gastroparesis associated with syphilis in an HIV-infected person with an undetectable viral load.

We present a patient with fully controlled HIV disease and a normal CD4 count whose initial treatment for syphilis failed. Biopsy-proven syphilitic colitis and severe gastroparesis developed, requiring the insertion of a temporary percutaneous gastrostomy tube. The patient responded to a course of high-dose aqueous crystalline penicillin followed by doxycycline, and he completely recovered. The occurrence of failure of conventional syphilis treatment in HIV-infected patients is discussed.