Infectious Proctitis
A 25-year-old man presented to the gastroenterology clinic with a 7-month history of fatigue, abdominal pain, and a change in bowel habits. He reported rectal pain, bleeding, and tenesmus; he initially had diarrhea but constipation had developed in the week before presentation. He also noted a 14-kg (30-lb) weight loss without night sweats or fevers. He reported a history of unprotected receptive anal intercourse. The rectal examination was notable for an anal fissure. Colonoscopy revealed severe ulcerative proctitis (Panel A), and biopsy specimens showed active proctitis with lymphocytic inflammation. Immunohistochemical staining was positive for Treponema pallidum (Panel B, arrow). Rapid plasma reagin testing was positive at a titer of 1:32, and a polymerase-chain-reaction assay of a sample obtained from a rectal swab was positive for Chlamydia trachomatis L serovars and negative for gonorrhea. Testing for human immunodeficiency virus was negative. A diagnosis of infectious proctitis associated with syphilis and lymphogranuloma venereum was made. The symptoms and endoscopic appearance of infectious proctitis may be similar to those of inflammatory bowel disease. The patient was treated with benzylpenicillin, azithromycin, and a 21-day course of doxycycline, which was followed by a complete resolution of symptoms.
