Patients at risk: males who have sex with males, anal-receptive intercourse, may be HIV positive
Pathogens:
(1) syphilis (Treponema pallidum)
(2) lymphgranuloma venereum (LGV, Chlamydia trachomatis L1, L2, L3).
Clinical features similar to inflammatory bowel disease (IBD):
(1) anorectal bleeding and/or pain
(2) purulent or mucoid discharge
(3) constipation
The endoscopic appearance is similar to IBD.
Histologic features of seen with STD colitis:
(1) minimal active chronic crypt centric damage
(2) lack of mucosal eosinophils
(3) submucosal plasma cells, endothelial swelling and perivascular plasma cells (requires biopsy that includes submucosa)
The diagnosis is established by serologic or molecular methods to identify the underlying pathogen.
The diagnosis also requires exclusion of other causes of colitis.
