Introduction

What is proctitis? 

Proctitis arises from the inflammation of the lining of the rectum, the lower end of the intestines, and just above the anus. The diagnosis of this condition is frequently correlated with inflammatory bowel disease (IBD). Proctitis is generally associated with pain, discomfort, and bloody rectal discharge, mainly in those who engage in anal sex. Although proctitis can occur in an acute (short-term) form, many cases include being chronic (long-lasting) form, where the pain is more persistent and disease progression is problematic.

On many occasions, proctitis is the result of something deeper: an infection, an autoimmune condition, or the side effect of medical treatment. Knowing the cause is the key to awareness, which we will explore in this article.^1,2,3

Causes

Although proctitis is often linked to IBD, it is not always the cause. When standard treatments do not work, doctors look at other possible reasons, such as infections (especially sexually transmitted ones), past radiation therapy, reduced blood flow, or even injury. In recent years, infections, particularly those spread through sexual contact, have become a more common and important cause of proctitis.¹

Infections

Infectious proctitis is primarily caused by bacteria, viruses, or parasites. Its prevalence is more common in those who are sexually active or already carry the human immunodeficiency virus (HIV). However, even without sexual contact, infections can occur, for example, through improper hygiene.⁴

Sexually transmitted infections (STIs)

STIs are infections that can be spread during sexual intercourse through the exchange of fluids or direct skin contact. Various STIs, such as gonorrhea, chlamydia, and syphilis, can show symptoms and cause inflammation associated with proctitis.⁵

• Gonorrhoea: transmitted through the mucosal surfaces (inner linings) of the genitalia in both men and women. Symptoms include rectal bleeding, diarrhoea, and tenesmus (feeling of pressure in the back passage, like you still need to defecate)⁶
• Chlamydia: similar to that of gonorrhoea, however, often silent, with mild diarrhoea and anal discharge may occur⁷ 
• Herpes simplex virus (HSV): HSV, either type 1 or type 2, can cause inflammation. Some people do not notice any symptoms at first, but many, especially women, may feel unwell during the initial infection, with flu-like signs such as tiredness, headaches, or muscle aches. After the first infection, the virus stays in the body within the nerve cells and can sometimes reactivate later on⁷
• Syphilis: caused by the spirochete Treponema Pallidum bacteria. Symptoms start with a painless sore (chancre) on the genitals, mouth, or rectum, along with nearby swollen lymph nodes. Without early treatment using antibiotics, syphilis can spread and affect other parts of the body, causing long-term damage to the brain, heart, or blood vessels^7,8 
• HIV: weakens the immune system, increasing the likelihood of infections and worsening symptoms

Non-STI infections

Proctitis can be triggered by infections not spread through sexual contact, such as through contaminated food or water (e.g. Salmonella, Shigella), viruses like cytomegalovirus (CMV), or rarely, parasites. If symptoms of diarrhoea and fever persist for more than 7 days, consider testing for the pathogens mentioned below. ⁹

• Bacterial (e.g., Salmonella, Shigella, Campylobacter)
• Viral (e.g., Cytomegalovirus (CMV), especially in immunocompromised patients)
• Parasitic (e.g., Entamoeba histolytica)

Non-infectious causes

Whilst infections are the most common cause of proctitis, sometimes the inflammation is due to conditions like inflammatory bowel disease (IBD), radiation therapy, ischaemic proctitis, or irritation from medications or treatments. These listed are not contagious; however, they can still lead to uncomfortable symptoms that require care and treatment.

Inflammatory bowel disease (IBD)

Inflammatory bowel disease is a chronic condition that causes inflammation in the digestive tract, alongside proctitis. Whilst the causes remain poorly understood, it is known to arise from the genetic factors, an overactive immune response, and environmental triggers like stress and diet. 

IBD is subdivided into two main types within proctitis:^10,11

• Ulcerative proctitis is distinguished from ulcerative colitis when the inflammation is limited to the rectum.  While ulcerative proctitis involves a smaller area of the bowel, compared to infectious causes, it can have an impact on daily life^12,13
• Crohn’s disease: Can affect any part of the digestive tract, from the mouth to the anus. Its association with proctitis can be dependent on whether the subject has perianal Crohn's, which affects the rectum. Symptoms of Crohn’s disease that overlap with proctitis include skin tags, anal fissures, anal fistulas, or abscesses, which only affect up to 20% of individuals with proctitis^10,14

Radiation therapy

The National Cancer Institute (NIH) states that radiation exposure can directly damage the lining of the rectum through therapy. Radiation proctitis is caused due to previous exposure to radiation therapy used for the treatment of rectal, prostate, and cervical cancers. This can happen weeks or even years after treatment. If you have developed this form of proctitis, then treatment follow-ups are usually managed through diet plans or medicine consultations with your doctor.¹⁵

Ischemic proctitis

Ischemic proctitis, known as reduced blood flow to the rectum, is uncommon due to the rectum having a rich blood supply from several nearby arteries. However, it can occur after major surgeries, including heart (aorta), or radiologic interventions. Other possible causes include radiation therapy, severe blood vessel diseases, or inflammation of blood vessels (vasculitis). Although rare, when it happens, it can cause severe rectal bleeding and pain, therefore requiring medical attention.^16,17

Symptoms of proctitis

Local gastrointestinal symptoms

• Constipation
• Passage of bloody stools
• Rectal discomfort or pain
• Diarrhoea or loose stools
• Frequent or urgent need to defecate¹⁸

Systemic symptoms (in some cases)

• Abdominal cramping (particularly on the left side)
• Fever
• Dehydration
• Tachycardia (faster heartbeat)
• Hypotension (low blood pressure)¹

Symptoms related to the underlying cause

• Genital ulcers (HSV)⁷
• Joint pain
• Eye inflammation (in IBD-related proctitis)

Summary

Proctitis is the inflammation of the rectum's lining, often linked to inflammatory bowel disease (IBD). It usually causes pain, discomfort, and bloody discharge, particularly in individuals who practice anal sex. Proctitis can be acute or chronic, with chronic cases presenting more persistent symptoms. The condition may arise from infections, autoimmune disorders, or treatment side effects. While IBD is a common cause, other potential reasons include sexually transmitted infections (STIs), prior radiation therapy, reduced blood flow, or injuries.

Infections are increasingly recognised as significant contributors to proctitis, particularly among sexually active individuals or those with HIV. Infectious proctitis can result from bacteria, viruses, or parasites, often affecting sexually active people. Common STIs causing proctitis include gonorrhea and chlamydia, which cause symptoms like rectal bleeding and discomfort. Herpes simplex virus may lead to inflammation with flu-like symptoms, while syphilis begins with painless sores. Non-STI infections can also cause proctitis, usually from contaminated food or water. Non-infectious causes include IBD, radiation therapy, and ischemic proctitis, which results from decreased blood flow. Symptoms of proctitis include gastrointestinal issues like constipation, bloody stools, rectal pain, diarrhoea, and an urgent need to defecate. Other systemic symptoms can include abdominal cramping, fever, and dehydration, depending on the underlying cause.

FAQs

Is proctitis contagious?

Having proctitis is not contagious; however, due to one of the main causes being sexually transmitted diseases, it can be spread through sexual contact. If you are a carrier of herpes, gonorrhoea, or chlamydia, it is important to recognise the symptoms carried from these infections and get tested as soon as possible and let your partner(s) know so they can also be checked.

What are the current treatments available?

The National Institute of Diabetes and Digestive and Kidney Diseases (NIH)  provides a comprehensive guide on medication and treatment availability suited to each different cause of proctitis.

• For IBD-related proctitis, doctors often prescribe anti-inflammatory medications such as steroids or immunosuppressants to reduce inflammation and maintain remission. Surgery may be a further decision if symptoms do not improve
• For infectious proctitis, antibiotics or antiviral medicines are available for a suitable treatment period
• Radiation proctitis is usually managed with medications or internal endoscopic procedures

Consult with your doctor and health service provider for recommended treatment plans based on your symptoms and the related inflammation.

How can I prevent proctitis?

If you engage in anal sex, you can lower your risk by practising safe sex using protection (condoms) and getting regular STI checks. For IBD-related proctitis, the condition can be managed through diet treatment plans and avoiding known triggers like certain medications. If you underwent recent radiation therapy for cancer, it is important to proceed with regular follow-ups to help catch any early signs of possible inflammation.