Table 1

 Common organisms causing sexually transmitted proctitis (it should be noted that more than one infection may be present)

OrganismCommon symptoms and signsInvestigationsRecommended first line treatment
bd, twice daily; EIA, enzyme immunoassay; HSV, Herpes simplex virus; IM, intramuscular; LGV, lymphogranuloma venereum; NAAT, nucleic acid amplification testing; PCR, polymerase chain reaction; RPR, rapid plasma reagin test; STI, sexually transmitted infections; TPPA, Treponema pallidum particle agglutination; TPHA, Treponema pallidum haemagglutination assay; VDRL, Venereal Disease Research Laboratories.
GonorrhoeaCommonly asymptomatic. Pruitis ani, constipation, mucopurulent anal discharge with or without bleeding, rectal pain and tenesmusCulture (gold standard) NAAT (not validated, always confirm with culture)Cefixime 400 mg stat or ceftriaxone 250 IM or spectinomycin 2 g IM
Chlamydia (non-LGV serovars)Commonly asymptomatic. Pruitus ani, mucoid discharge, perianal painNAAT (not validated)Azithromycin 1 g stat or doxycycline 100 mg bd for 1 week
LGVSystemic symptoms (Fever and malaise) Purulent, often bloodstained anal discharge. Severe pain, tenesmus, constipation. Symptoms and signs may be mistaken for those of inflammatory bowel diseaseNAAT as for chlamydia—refer to reference lab if positive for typingDoxycycline 100 mg bd for 3 weeks
SyphilisPrimary syphilis—anorectal chancres commonly asymptomatic, may be associated with pain or discomfort, itching, bleeding, discharge and tenesmus. Secondary syphilis—snail track ulcers and mucous patches. Perianal condylomata lata. Generalised rash, fever and lymphadenopathy may be presentDark ground microcopy if ulcer present serological tests: RPR/VDRL>70% sensitive in primary syphilis, 100% sensitive secondary syphilis EIA/TPPA/TPHA. >70% sensitive in primary syphilis, 100% in secondary syphilis. Stay positive after treatment and in latent infectionProcaine penicillin IM 750 mg daily for 10 days or benzathine penicillin 2.4 g IM stat or doxycycline 100 mg bd for 14 days Advise should be sought if the patient is HIV infected as treatment regimes may vary
Herpes simplex virusVesicular lesions, severe pain, difficulty in passing a bowel motion, tenesmus, discharge, viraemic symptoms such as fever and lymphadenopathyViral culture or PCRAciclovir 200 mg 5 × daily for 5 days