Anal Discharge: What Causes It and What to Do

Types of anal discharge and what they suggest

Common causes

Hemorrhoids

Swollen blood vessels in and around the anus can make mucus and prevent the anus from closing completely, so moisture and small amounts of stool leak out. Expect itching, bright red blood on toilet paper and a soft lump at the anus. See hemorrhoids.

Anal fistula and abscess

An anal abscess is a collection of pus beside the anus, usually from an infected anal gland. It causes constant throbbing pain and a tender lump. When it bursts or is drained, it often leaves an anal fistula: a small tunnel from inside the anal canal to the skin. The fistula keeps leaking pus or blood-stained fluid from a small hole near the anus, causing itching and irritation. Fistulas rarely heal without surgery. See anal fistula and perianal abscess.

Anal fissure

A small tear in the lining of the anus causes sharp pain during and after bowel movements, a little bright red blood, and sometimes a small discharge from the tear. See anal fissure.

Fecal seepage

Small amounts of liquid stool can leak and stain underwear, especially after a bowel movement. Causes include incomplete wiping, hemorrhoids or skin tags, a slightly weak anal sphincter after childbirth or surgery, diarrhea, and too much caffeine. See fecal incontinence.

Skin conditions

Itching around the anus (pruritus ani), eczema, psoriasis or fungal infection can cause moist, weeping skin that feels like discharge.

Less common but important causes

• Proctitis: inflammation of the rectal lining causes mucus or pus discharge, urgency, a constant feeling of needing to pass stool (tenesmus) and bleeding. Causes include STIs, inflammatory bowel disease and radiation therapy.
• Sexually transmitted infections: gonorrhea, chlamydia (including LGV), herpes and syphilis can infect the rectum after anal sex, causing discharge, pain and bleeding. Some cause no symptoms.
• Crohn's disease: often causes complex fistulas, abscesses and skin tags around the anus.
• Ulcerative colitis: bloody, mucus-filled diarrhea with urgency.
• Rectal prolapse: the rectal lining slips out through the anus, causing mucus discharge and a visible bulge.
• Anal warts: can cause moisture, itching and bleeding.
• Cancer: anal or rectal cancer can cause mucus, bleeding, a lump and changed bowel habits. It is uncommon but important to rule out, especially after age 45.

How doctors find the cause

A clinician will ask what the discharge looks like, how long it has been present, whether there is pain, bleeding or fever, about bowel habits, previous abscesses, sexual history and bowel disease in the family. They will:

• Look at the skin around the anus for openings, tags, fissures, warts or prolapse
• Do a gentle finger examination of the anal canal
• Look inside with a short scope (anoscopy or proctoscopy)
• Take swabs for gonorrhea, chlamydia and herpes if relevant
• Arrange further tests if needed: stool tests, blood tests, colonoscopy, or an MRI to map a fistula

Treatment and home care

Treatment targets the cause:

• Hemorrhoids and fissures: a high-fiber diet, plenty of fluids, stool softeners, sitz baths and topical treatments. Banding or surgery for persistent hemorrhoids.
• Abscess: surgical drainage, often done urgently. Antibiotics alone are not enough.
• Fistula: surgery, such as fistulotomy or a seton (a thread that drains the tract while it heals).
• STIs: antibiotics or antivirals, with partner testing.
• Inflammatory bowel disease: anti-inflammatory and immune-modifying medicines.
• Seepage: bowel habit changes, pelvic floor exercises, bulking agents.

Home care for mild discharge and staining

• Clean gently after bowel movements with water or unscented wet wipes, then pat dry.
• Avoid scented soaps, bubble baths and harsh scrubbing.
• Wear loose cotton underwear. A small cotton pad or gauze tucked between the buttocks absorbs moisture.
• A thin layer of barrier ointment, such as zinc oxide, protects irritated skin.
• Eat more fiber and drink fluids to keep stools soft and formed.
• Cut back on caffeine and alcohol if stools are loose.

Frequently asked questions

What causes clear mucus discharge from the anus?

Clear or white mucus usually comes from irritation of the anal or rectal lining. Hemorrhoids, irritable bowel syndrome and rectal prolapse are common causes. Proctitis and inflammatory bowel disease cause mucus with urgency or blood. A small amount occasionally is normal, but persistent mucus should be checked.

Is anal discharge a sign of cancer?

It can be, but it usually is not. Most anal discharge comes from hemorrhoids, fistulas, fissures or stool seepage. Anal and rectal cancers can cause mucus, bleeding and a change in bowel habits, so persistent discharge, especially after age 45 or with blood or weight loss, should be examined.

Why is pus coming from near my anus?

Pus from a small opening near the anus is most often an anal fistula, usually after an anal abscess. It tends to drain on and off and may itch or hurt. A painful swollen lump with fever suggests a new abscess, which needs urgent drainage.

Can an STI cause anal discharge?

Yes. Gonorrhea, chlamydia, herpes and syphilis can infect the rectum, usually after receptive anal sex, causing discharge, pain, bleeding and a feeling of needing to pass stool. Some rectal infections cause no symptoms. Testing uses a rectal swab, and treatment is with antibiotics or antivirals.