Rectal discharge refers to any substance, aside from feces, that comes out of your rectum. Your rectum is last part of your digestive system before your anus, which is the opening at the end the system.

It usually presents as mucus or pus that you may notice in your underwear or on your stool. You may also feel the urge to have a bowel movement, but only pass mucus or a very small amount of stool.

It’s a common symptom of irritable bowel syndrome (IBS), but infections, including sexually transmitted infections (STIs) and other conditions, can also cause it.

Some STIs that affect your rectum or anus can cause discharge. They’re usually transmitted through anal sex, but an infection in the genital region can also spread to the anal region.

STIs that can affect your rectum or anus include:

Rectal discharge may be your only symptom. Other symptoms can include:

See a doctor if you think you may have an STI. Early diagnosis and treatment can help you avoid complications and reduce your risk of passing it on to others.

Infections associated with foodborne illness can cause rectal discharge, often along with nausea and vomiting, cramps, and diarrhea.

Foodborne illness, commonly known as food poisoning, are infections that can be caused by many different types of bacteria, viruses, and parasites.

The most common infections include:

Some cases of foodborne illness resolve on their own, but others may require antibiotics. In either case, it’s important to stay hydrated to replace fluids lost from vomiting or diarrhea.

IBS is a chronic disorder of the large intestine that doesn’t have a clear cause. But experts believe that stress, large meals, and certain goods can trigger it.

Common symptoms of IBS include:

See your doctor if you experience any of these symptoms regularly. Symptoms of IBS can often be managed with a combination of home remedies and lifestyle changes, probiotics, medication, and mental health therapies.

Hemorrhoids are swollen veins in your anus or lower rectum. They’re very common, affecting 3 out of 4 adults at some point, according to Mayo Clinic.

They’re usually caused by increased pressure from straining during bowel movements and chronic constipation or diarrhea. Pregnancy and obesity are risk factors.

Common symptoms of hemorrhoids include:

  • pain around the anus
  • anal swelling or lump
  • severe anal itching
  • rectal discharge
  • bleeding during bowel movements

Hemorrhoids can usually be managed with home remedies, but it’s important to see a doctor if you experience rectal bleeding, especially for the first time. Rectal bleeding is sometimes a sign of a serious underlying condition.

An anal abscess is an infected sac filled with pus near your anus. It’s usually caused by an acute infection in the anal glands.

In some cases, an anal abscess develops into a fistula. An anal fistula is a small channel that connects the infected anal gland to an opening on the skin. Fistulas can also be caused by other medical conditions.

Symptoms of an anal abscess include:

  • rectal discharge or bleeding
  • pain and swelling around your anus
  • constipation

Treating an abscess involves draining the pus, which can usually be done quickly by your healthcare provider in their office.

Symptoms of a fistula include:

  • anal pain, often severe
  • pain during bowel movements
  • bleeding
  • foul-smelling discharge from an opening in the skin near the anus
  • fever

See your doctor if you experience symptoms of a fistula, as these require surgical treatment.

Inflammatory bowel disease (IBD) is the term for a group of conditions that that result in chronic inflammation of your gastrointestinal (GI) tract. These main types of IBD are ulcerative colitis and Crohn’s disease.

Crohn’s disease can affect any part of your GI tract, from your mouth to your anus, but most often affects the small intestine. Ulcerative colitis affects your large intestine and rectum.

The symptoms of IBD can vary depending on the severity of the inflammation and its location.

Common symptoms include:

  • abdominal pain and cramping
  • diarrhea, often with pus or mucus
  • blood in your stool
  • reduced appetite and weight loss
  • fever
  • fatigue

IBD can lead to complications when not properly managed. Symptoms of IBD can be managed with a combination of diet and lifestyle changes. Medical treatment for IBD includes medication and, occasionally, surgery to remove damaged parts of the GI tract.

Rectal prolapse occurs when your rectum falls from its original position, causing it to partially or completely slip through your anus. It’s most common in women over 50 with a history of chronic constipation, but can also occur in younger people.

You may first notice the feeling of a bulge or see a mass of reddish-colored tissue coming from the anus. Symptoms may come and go at first, but worsen over time. Fecal incontinence is another symptom.

A prolapsed rectum usually requires surgical treatment.

Anal cancer can cause rectal discharge, but it’s generally the least likely cause. According to the American Cancer Society, the lifetime risk of developing anal cancer is only 1 in 500.

Anal cancer causes symptoms similar to those caused by more common conditions, such as hemorrhoids and IBS.

These symptoms include:

  • a change in bowel habits
  • thin stools
  • pain or pressure in the anus
  • a lump near the anus
  • rectal bleeding or discharge
  • itching

The risk of anal cancer is very low, though certain things can increase your risk. These include your age, smoking, and exposure to human papillomavirus (HPV).

It’s best to follow up with your healthcare provider if you notice any kind of rectal or anal discharge, especially if you’ve never experienced it before.

Based on your symptoms and medical history, they may perform a range of tests to narrow down a diagnosis.

These tests may include:

Rectal discharge is usually a symptom of an underlying condition affecting your GI tract or an infection. To avoid any potential complications, it’s best to see your healthcare provider for an accurate diagnosis.

If you’re not comfortable talking to them about your symptoms, you can always ask for a referral to a specialist who’s used to dealing with rectal and anal health concerns.