Proctitis: symptoms, causes and how you test for it

Proctitis is an inflammation of your rectum, the last stretch of bowel just above your anus. If you have had receptive anal contact in recent weeks, an STI sits at the top of the list of possible causes. The 2021 European guideline names gonorrhoea, chlamydia, syphilis and herpes as the most common pathogens in that spot (de Vries, 2021).

And that is exactly where things go wrong. Search for proctitis in Dutch and you land on hospital pages about chronic bowel disease. Those pages are not wrong. They simply answer a different question than yours.

We are a testing provider, so let us say up front how it works: a normal STI test from urine or blood does not look in your rectum. That needs a separate swab. On this page you will read what proctitis is, which symptoms fit, how to tell an STI cause from a bowel cause, and which test belongs to which pathogen.

What is proctitis?

Proctitis is an inflammatory syndrome of the anal canal, the rectum, or both. That is how the European guideline defines it (de Vries, 2021). In Dutch it is called endeldarmontsteking, and you will also see the phrase "endeldarm ontstoken" used.

The inflammation itself is a reaction of the mucous membrane. What set that reaction off varies enormously: a bacterium, a virus, a chronic bowel disease, radiotherapy to the pelvis, or damage to the lining.

So the location tells you little about the cause.

The same inflamed rectum can be an STI in one person and the first sign of ulcerative colitis in another. That is the heart of this page, and the reason we do not hand you a symptom checklist to sort yourself with.

Which symptoms fit proctitis?

Proctitis comes with itching or pain around the anus, an urge to go with nothing arriving, blood or mucus with your stool, constipation, and discharge from the anal canal. That list comes straight from the European guideline (de Vries, 2021). Together they point to inflammation. They do not point to the pathogen.

That empty urge has its own name: tenesmus. You feel you need to go, you sit down, and little or nothing comes. It is one of the most recognisable symptoms and one of the most miserable.

What frightens people most is blood. With an inflamed rectum, that blood usually sits on the outside of the stool or on the paper, not mixed through it.

Persistent blood loss always belongs with your GP. Not because it is usually serious, but because you cannot make that distinction yourself and a doctor can actually look.

What causes proctitis?

The causes fall into three groups: sexually transmitted infections, chronic bowel disease, and damage to the lining from something like radiotherapy. In people with receptive anal contact the first group is the largest, and within it gonorrhoea and chlamydia are by far the most seen (de Vries, 2021).

The table below sets them side by side. Look at that last column: it tells you which sample is needed, and that is precisely what a standard STI test looks past.

Two things stand out. Gonorrhoea, chlamydia and LGV all three need a swab of the rectum, not urine. And syphilis and herpes need something different again. One test does not cover this list.

When does proctitis point to an STI?

From the symptoms alone you cannot tell. What does give direction are two questions about the weeks before the symptoms started. They do not replace a doctor, but they do tell you which side should be investigated first.

Question 1: was there receptive anal contact in recent weeks? That means a penis, but also fingers or toys. The guideline names all those routes (de Vries, 2021). Using a condom does not rule it out, because these infections also spread without penetration.

Question 2: did the symptoms start within days to weeks after that? Infectious proctitis usually gets going inside that window. A pattern that has been simmering for months and slowly worsening fits it less well.

Two yesses means: have the STI side ruled out first, with the right sample. Two nos, with blood or mucus that has persisted for weeks, means this is a question for your GP, who can consider bowel disease.

Not sure? Then do both. You can arrange the STI side yourself; the bowel side belongs with a doctor. They do not cancel each other out.

Why does a normal STI test miss a rectal infection?

Because a urine test looks at the urethra and a blood test looks at antibodies in your blood. If the infection sits in the lining of your rectum, neither of them picks anything up. For gonorrhoea and chlamydia in that spot, a swab of the anus is needed, which the lab then examines with a PCR.

This is not our idea. It is the reason extragenital testing exists as a separate subject in the scientific literature (Chan, 2016).

And it gets more awkward. The European guideline states that the majority of rectal chlamydia and gonococcal infections cause no symptoms at all and can only be found with a laboratory test (de Vries, 2021). A study on Reunion island even found that every extragenital infection it detected ran without symptoms (Calas, 2021).

So no symptoms is not an all-clear here. And a clean urine test says nothing about your rectum.

How do you test for a rectal STI?

With a swab of the anus. A cotton swab is inserted a short way into the anal canal and rotated, after which the lab checks it with a PCR for gonorrhoea and chlamydia. It takes seconds and it is not painful, though it does feel strange.

Taking it yourself is allowed, and it works well. In a 2024 study, throat and rectal swabs taken at home proved no worse than swabs taken in a healthcare setting (Orser, 2024).

Our test for chlamydia, gonorrhoea and trichomonas detects those infections with a PCR. If you want your anus checked specifically, choose an anal swab when ordering, because the standard sample looks at the genital side. How that works in practice is in STIs in the anus: which ones sit there and how you test.

Syphilis and HIV need a blood test, and herpes needs a swab of a blister. Those do not sit in the same test.

What is LGV and why does it matter here?

LGV stands for lymphogranuloma venereum. It is a more aggressive variant of chlamydia, caused by types L1, L2 and L3, and it does give heavy proctitis symptoms: severe pain, blood and a strong urge. A normal chlamydia test sees that it is chlamydia, but not that it is this type.

In the Netherlands the RIVM tracks the figures. Between 2011 and 2017 the number of LGV diagnoses rose from 86 to 270, and the share of patients without symptoms climbed over those same years from 31.4 to 49.3 percent (van Aar, 2020).

That last number is the interesting one. LGV had a reputation as the variant you cannot miss, because the symptoms are so heavy. By now roughly half of the cases found have no symptoms at all.

Across Europe, LGV is probably badly underdiagnosed: in a multi-country study, 25.6 percent of chlamydia-positive rectal swabs from MSM turned out to be LGV (Cole, 2020). We work this out in LGV: the STI a normal chlamydia test misses.

How is proctitis treated?

That depends entirely on the cause, and treatment belongs with a doctor. A bacterial cause like gonorrhoea or chlamydia is treated with antibiotics; with LGV that course runs longer. Herpes calls for antiviral medication. Chronic bowel disease or radiation damage follows a completely different path.

Which is exactly why guessing works out badly here.

A course that suits ordinary chlamydia is too short for LGV. An anti-itch cream does nothing against a bacterium. And the other way round: antibiotics do not help ulcerative colitis.

We test, we do not treat. You take a positive result to your GP or a sexual health clinic, and they decide the treatment. Tested positive for an STI: what now covers what that step looks like in practice.

Two people with the same urge

Picture two people reporting the same thing on a Tuesday morning: 6 days of empty urge, some mucus, and 2 streaks of blood on the paper. No fever. The same complaint, down to the detail.

For the first, it started ten days after a weekend with someone new, which involved receptive anal contact. For him, a urine test looks past the spot where the risk sat. Only a swab of the anus gives an answer, and that answer comes within days.

For the second, there has been no partner at all for four months, and looking back the blood has been showing up occasionally since May. For her an STI is unlikely and the GP is the first step, with a very different question in mind.

The difference was never in the complaint.

It sat in what came before it. That is why I would rather ask you the two questions on this page than have you tick off a symptom list. Two identical rectums can need two completely different answers.

Can you get proctitis without anal sex?

Yes, and it happens more often than people think. Chronic bowel disease, pelvic radiotherapy, long-term laxative use and damage to the lining can all inflame the rectum with no sex involved at all.

The reverse holds too, and it gets missed a lot. The guideline points out that transmission can also run via fingers and toys, and that women who have anal sex are at risk just the same (de Vries, 2021). Rectal STIs are not an MSM-only subject, even if most research covers that group.

Dutch GP guidance handles the bowel side of this story. We handle the STI side. For the full picture you sometimes need both.

Further reading in this cluster

If itching is your main complaint, go to anal itching. If it is blisters or sores, herpes around the anus is the piece you want.

For the infection behind this most often, read anal chlamydia. For its aggressive variant: LGV. And for the practical side: STIs in the anus and how you test.

If your complaint fits the wider list better, STI symptoms in men and women gives the overview, and which STI test you need when helps you choose.

References

• de Vries HJC, et al. 2021 European Guideline on the management of proctitis, proctocolitis and enteritis caused by sexually transmissible pathogens. Journal of the European Academy of Dermatology and Venereology, 2021. PMID 34057249.
• van Aar F, et al. Increasing trends of lymphogranuloma venereum among HIV-negative and asymptomatic men who have sex with men, the Netherlands, 2011 to 2017. Eurosurveillance, 2020. PMID 32290900.
• Cole MJ, et al. Substantial underdiagnosis of lymphogranuloma venereum in men who have sex with men in Europe: preliminary findings from a multicentre surveillance pilot. Sexually Transmitted Infections, 2020. PMID 31235527.
• Chan PA, et al. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature. Infectious Diseases in Obstetrics and Gynecology, 2016. PMID 27366021.
• Orser L, et al. Testing for extragenital Neisseria gonorrhoeae and Chlamydia trachomatis: At-home pharyngeal and rectal self-swabs are non-inferior to those completed in healthcare settings. PLoS One, 2024. PMID 38768150.
• Calas A, et al. Prevalence of urogenital, anal, and pharyngeal infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium: a cross-sectional study in Reunion island. BMC Infectious Diseases, 2021. PMID 33478403.
• RIVM, STI surveillance Netherlands. Accessed August 2026.

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