results have been reported, with 89% of patients reporting improvement and 36% reporting full

continence.38 SNS may be offered to patients both with and without evidence of sphincter defects. Tibial

nerve stimulation has also been shown to lead to improvement in anal continence, however this therapy

is currently not approved for use in the United States.39

In patients with severe incontinence for whom alternative methods have failed, creation of a sigmoid

colostomy may improve quality of life and allow them to resume normal daily activities.

Sexually Transmitted Diseases of the Anorectum

The annual incidence of sexually transmitted diseases is approximately 15 million cases in the United

States. As anal erotic practices have increased, the incidence of sexually transmitted diseases of the anus

and rectum has also increased. These are typically the result of anal receptive intercourse, but in some

instances represent contiguous spread from genital infections.

Gonorrhea

Gonorrhea is caused by the gram-negative intracellular diplococcus Neisseria gonorrhoeae, with an

incubation period that ranges from 3 days to 2 weeks. Symptomatic anorectal gonococcal infection

results in pruritus or tenesmus, accompanied by a mucoid and sometimes bloody rectal discharge. Left

untreated, a more advanced systemic infection can occur resulting in such conditions as endocarditis,

pericarditis, and a unilateral migratory gonococcal arthritis of large joints.

Anorectal gonorrhea results in a thick yellow mucopurulent discharge from the anus. This purulent

material is often able to be expressed from the anal crypts and can be visualized directly by applying

gentle external pressure while viewing the distal anorectum through an anoscope. Sigmoidoscopy may

reveal a proctitis extending to no more than about 10 cm from the anal verge. Although these findings

may be mistaken for an ulcerative or nonspecific proctitis, abscesses, fistulae, and ulcers are not typical.

Diagnosis is confirmed by culture on a Thayer–Martin medium plate incubated in a carbon dioxide

environment.

Due to the increasing prevalence of penicillinase-producing N. gonorrhoeae, penicillin G is no longer

recommended. First-line treatment is a single intramuscular injection of 250 mg of ceftriaxone.

Alternative treatments that have been proposed include single oral dose of 500 mg of cefixime or a

single oral dose of a fluoroquinolone. Because of the high rate of concomitant infection with Chlamydia,

patients should be given appropriate treatment for Chlamydia as well. Sexual partners from the past 60

days should also be treated.

Chlamydia/Lymphogranuloma Venereum

Chlamydia trachomatis is the most common sexually transmitted bacterial infection worldwide. In the

United States, male homosexuals account for the majority of rectal Chlamydial infections. With 15

known serotypes, anorectal Chlamydia infection can cause proctitis (serotypes D-K) or

lymphogranuloma venereum (LGV) (serotypes L1–L3). Transmission of disease is through anoreceptive

intercourse, with an incubation period ranging from 5 days to 2 weeks; secondary involvement can also

occur as a late manifestation of genital infection.

Symptoms of non-LGV anorectal infection include rectal pain, tenesmus, and fever, although a

substantial number of infected patients will be asymptomatic. Examination reveals enlarged matted

inguinal lymph nodes and proctosigmoidoscopy shows an erythematous rectal mucosa without frank

ulcerations. Patients with LGV also complain of pain, fever, and tenesmus but often have a slight

mucopurulent discharge and hematochezia. The inguinal lymph nodes in LGV are often more enlarged

as they fuse into a large indurated mass with overlying erythema. Evaluation of the rectal mucosa

reveals a more severe granular proctitis with mucosal friability and frank ulceration. Left untreated, the

disease may progress to fistulae, abscesses, and late rectal strictures. In this setting, LGV may be

confused for perianal Crohn’s disease, however the marked inguinal lymphadenopathy may help

distinguish LGV from Crohn’s.

Treatment of Chlamydia infection is with a single oral dose of azithromycin (1 g) or doxycycline (100

mg) twice a day for 7 days. Alternative therapy includes erythromycin or a fluoroquinolone. Treatment

of LGV is a 21-day course of either erythromycin or doxycycline. Sexual partners also require treatment

to prevent reinfection.

Herpes Simplex Virus

Herpes is the most prevalent sexually transmitted disease in the United States where it is estimated that

20% of the general population are affected. The majority of anorectal herpes infections are caused by

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HSV-2 with only about 10% being caused by HSV-1. Transmission is through autoinoculation or direct

contact with an infected individual who is shedding the virus, and the clinical infection may begin 4 to

21 days following anoreceptive intercourse. Patients present with small red vesicles which may be

clustered or scattered in the perianal skin, anal canal or perineum, are extremely painful to touch.

Proctoscopy reveals friable mucosa, ulceration, and the mucopurulent discharge. These findings will be

limited to the distal 10 cm on proctoscopy. Tender inguinal adenopathy occurs in up to 50% of patients

with HSV proctitis. Recurrent attacks are generally milder and shorter in duration.

Diagnosis is made on clinical examination, finding multinucleated giant cells with intranuclear

inclusion bodies on Pap smear, a positive Tzank preparation or a positive culture. As the acute infection

is self-limited, treatment includes warm sitz baths and oral analgesics. The use of antiviral medications

has been shown to shorten the length of symptoms, but does not affect recurrence rates. Acyclovir (400

mg five times/day for 10 days) is most commonly used for initial infection. Recurrent attacks may be

treated with acyclovir (200 mg five times/day) or valacyclovir (500 mg twice/day). Suppressive

antiviral therapy may be considered in patients who have more than five attacks per year.

Condyloma Acuminata

7 Anal condylomata acuminate or “warts” are caused by the human papilloma virus (HPV). HPV is a

papovirus, and more than 80 subtypes of HPV have been identified. Serotypes 6 and 11 are most

commonly associated with the benign, exophytic condylomata of the anogenital region. Serotypes 16

and 18 have been associated with more aggressive lesions that can progress to invasive squamous cell

cancers.

The primary mode of transmission of anogenital HPV is sexual intercourse. Inoculation of the anal

epithelium allows entry of the HPV into the basal cell layers. As these cells proliferate viral replication

occurs in the nucleus. The basal cells then migrate toward the surface and infective particles are

released in the form of visible warts. Mature infectious particles are found in the surface layers of these

lesions.

Condyloma acuminata are easily recognized as epithelialized cauliflower-like projections. They may

be flat, raised, sessile or pedunculated, and range in size from millimeters to a large fungating lesions

known as giant condyloma acuminatum (Buschke–Lowenstein). They may be in clusters or grow to

cover the perineum and anal canal in a “carpet-like” fashion. The warts may be asymptomatic or may

cause pruritus, bleeding, or discharge. Anoscopy is important in evaluating for lesions within the anal

canal.

The goal of treatment is removal of all gross disease while minimizing morbidity, although this does

not ensure eradication of infection. Tangential excision, cryotherapy, or fulguration of small lesions

with local anesthesia can be performed as an office procedure with little discomfort to the patient.

Larger lesions are treated by excision in the operating room, while electrodessication is performed of

any remaining smaller condyloma.

Topical agents such as podofilox and imiquimod can be applied by the patient, but neither is approved

for use in the anal canal. Imiquimod is an immune response modifier that increases local production of

interferon. Complete response can be expected in 50% of patients treated with imiquimod, with 11% of

patients experiencing a recurrence. It can be used as initial treatment with electrodessication reserved

for those who have incomplete response, or following destructive treatment and epithelial healing to

treat remaining or recurrent disease.40

Anal Intraepithelial Neoplasia

The role of HPV in the development of cervical cancer in females has been clearly established, however

its significance in the development of anal cancer is not as well defined. Serotypes 16 and 18 have a

higher propensity to initiate the development of carcinoma, and have a predilection for the less stable

epithelium of the upper anal canal transition zone rather than the modified skin of the lower anal canal

anoderm. They may, however, be identified in the anal skin margin as well.

The incidence of anal cancer in HIV-positive homosexual males is estimated to be 38 times that of the

general population and twice the risk in HIV-negative homosexual males.41 HPV infection has been

reported in 93% of HIV-positive homosexual males compared with 60% of HIV-negative homosexual

males.42 Anal intraepithelial neoplasia (AIN), a precursor to the development of anal cancer, also has a

markedly increased incidence in HIV-positive individuals. It is felt that as HIV disease has become a

chronic, manageable condition, patients are living long enough to progress from AIN to anal cancer.

Some have therefore recommended screening and surveillance programs similar to those for cervical

cancer.

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