There has been a constant increase in the number of patients treated for sexually transmitted diseases. Over 500,000 cases of sexually transmitted infections (STIs) are reported annually in the EU countries alone (1, 2).

The local manifestation of the infection is not limited to the genitals. The presented symptoms depend on the site of pathogen entry, with possible involvement of the gastrointestinal mucosa, therefore such a diagnosis should also be considered in patients presenting with symptoms of anoproctitis. Despite their high prevalence, the surgeons’ awareness of this group of diseases, trends in sexual behaviours and the epidemiology of STIs is still insufficient. These elements are, however, of key importance for the identification of risk groups, proper diagnosis, treatment and limiting the further spread of infection. These measures are based on the knowledge of the human immunodeficiency virus (HIV), which characterises the high STI risk group and may affect the clinical picture presented by the patient both in the case of co-infection and superinfection.

STIs with anorectal manifestations usually result from receptive anal intercourse, which is practiced by men who have sex with men (MSM), as well as heterosexual persons and transgender women (3). Oral-anal intercourse and, in the case of gonorrhoea, transmission, e.g., via objects covered with infected vaginal discharge, are also possible routes of transmission (4-6).

The reported symptoms will differ, depending on the extent of bowel inflammation. Patients most often mention discomfort, anal pain, fresh blood during bowel movements, a feeling of painful tenesmus, or the presence of mucous and purulent discharge in the stool. These symptoms may vary in intensity or may not occur at all despite active infection (7, 8). This, along with the fact that some symptoms overlap with non-infectious anorectal conditions (such as inflammatory bowel disease, hemorrhoidal disease, anal fissure, anorectal cancers), may delay the diagnosis. It is also important for proper therapeutic management to be aware of frequent co-infections, which affect up to 40% of patients in the high-risk population (9).

In addition to appropriate diagnosis and in the absence of conservative treatment complications, the specific features of this group of pathologies also indicate the need for counselling on pathogen transmission and diagnostic investigations in sexual partners.

The following part of the paper will discuss the most common bacterial STIs, which are the reason for visiting a proctologist.

Gonococcal proctitis, caused by Gram-negative bacilli known as Neisseria gonorrhoeae (N. gonorrhoea), is one of the most common STIs. Epidemiological data in Poland indicate a much higher ratio of infected men to women (14:1) than in other EU countries (10). The fact that at least half of men and up to 95% of women with proctitis are asymptomatic is the reason for a large pool of carriers and contributes to the increasing incidence rates (6).

Symptoms, if present, usually appear within 5-10 days of infection and include pruritus, sometimes rectal pain, a feeling of incomplete bowel movement, and mucopurulent discharge. Some patients report slight bleeding during bowel movements. Proctoscopy in the range of up to 10 cm may reveal indistinct vascular pattern, hyperaemia and contact bleeding of the mucous membrane, which is covered with mucopurulent secretion to a varying degree.

Diagnostic workup involves collecting samples for culture on a selective medium or for N. gonorrhoeae DNA detection assays, especially in the case of oligo- or asymptomatic gonorrhoea (11, 12). Infection limited to the anorectal region is observed in more than 70% of MSM cases compared to only a small percentage of women (6). Therefore, samples for testing should be taken from the urethra or urine, rectum and pharynx, i.e. sites involved in sexual practices (13).

In addition to reaching the diagnosis, microbiological testing allows for assessing the pathogen’s drug susceptibility, which is important in view of the increasing resistance of the diplococcus to other antibiotics (14). Samples are obtained by inserting a swab to a depth of about 3 cm into the anal canal, and then rubbing it against the epithelium around the circumference of the anorectal ring for about 10 seconds. Visual anoscopic inspection or taking a swab from the rectum are not required (15, 16). Once diplococcal infection is confirmed, the diagnosis should be extended with tests for other STIs (syphilis, chlamydia, HIV, hepatitis B, hepatitis C). To prevent further spread of the disease, testing should be recommended in persons who had sexual intercourse with the patient in the month preceding the diagnosis (this period is extended to 90 days in sexual partners of asymptomatic patients). In addition, patients are advised to abstain from sexual intercourse from the time of diagnosis until 14 days after treatment completion.

The most common therapeutic regimen consists of a single intramuscular injection of 1 g of ceftriaxone with 2 g of oral azithromycin.

Molecular testing to confirm eradication 2 weeks after antibiotic therapy is recommended in patients whose symptoms have resolved, and if positive, a microbiological test with antimicrobial susceptibility testing (AST) should be performed. In the case of persistent symptoms, culture and AST are performed 3-7 days after treatment completion (17).

The intracellular bacterium Chlamydia trachomatis is the cause of two clinical entities, which differ, e.g. in severity. As with gonorrhoea, asymptomatic infections contributing to the spread of infection are observed. The route of transmission is also common for both pathogens.

In addition to urethritis and cervicitis, serotypes A-K are the etiological factor of benign proctitis. This type of infection is the most prevalent and is usually asymptomatic. Rarely reported symptoms include anal pain, the feeling of straining during bowel movement and fever. The macroscopic picture of the mucosa can vary from normal to non-specific signs of inflammation, with hyperaemia and mucosal fragility (fig. 1).

Among all anatomical sites of chlamydia in the MSM group, rectal infection is reported in almost 10%. A similar percentage is seen among women, with common coexistence with urogenital tract infection (18, 19).

A much more aggressive course has been reported for L1-L3 genotypes, which, by translocation from the mucosa to deeper tissues, penetrate into regional lymph nodes, causing lymphogranuloma venereum (LGV).

Compared to 20 years ago, when LGV cases were reported almost exclusively in tropical regions, it is now also observed in highly developed countries and mainly affects the MSM population, who are usually HIV-positive (20). It is likely that HIV itself is a factor promoting infection with L1-L3 genotypes, although this has not yet been fully confirmed (21).