Will doxycycline treat hemorrhoidal infection?

Proctitis? Hemorrhoids don't generally get infected. Maybe rectal inflammation/infection (proctitis)? If so, or if you have an anal fissure, doxycycline might help. If under a doctor's care, follow his or her advice. If not, see a doctor now. If your anus has been sexually exposed, get tested for STD; doxycycline is the treatment of choice for rectal chlamydia.