Symptoms · Back passage
Pain, swelling or bleeding at the back passage
The short answer
Constant, throbbing pain with a tender lump beside the anus, especially with fever, is often an abscess (a collection of pus). It needs to be drained, usually the same day. Pain when passing stool with a little bright red blood is more often an anal fissure (a small tear) or piles. See a doctor to find out which. Go to the emergency room if the pain is severe, you have a fever, or the swelling is spreading. Bleeding from the back passage should always be checked by a doctor.
How patients describe it
- A painful lump next to the back passage
- Throbbing pain when I sit
- Pain when I pass stool
- Bright red blood on the paper
- Pus or fluid leaking near the anus
- Piles
Go to the emergency room now if you have
- Severe throbbing pain with a hard, hot, red swelling beside the anus
- Fever or chills
- Redness spreading over the buttock or towards the groin
- You cannot pass urine or stool
- Heavy bleeding that does not stop, or dizziness with bleeding
- Diabetes or a weak immune system with a painful swelling here
What can cause it
Anal abscess
Constant throbbing pain, a tender lump beside the anus, and often fever. Pain is worse when sitting.
Next step: Urgent examination and drainage of the pus.
Anal fistula
A small opening beside the anus that keeps leaking pus or fluid, often after an abscess.
Next step: See a surgeon; a scan may be needed.
Anal fissure
A sharp, burning pain during and after passing stool, with a streak of bright red blood.
Next step: Softer stools, warm baths and creams; see a doctor if it continues.
Piles (haemorrhoids)
Bleeding, a soft lump or itching around the anus. A clotted pile is a painful hard lump.
Next step: Examination; most settle with simple measures.
What you can do now
- Sit in a warm bath 2–3 times a day, especially after passing stool
- Keep stools soft with fibre and plenty of fluids, and do not strain
- Do not squeeze, cut or burst a lump yourself
- Do not ignore bleeding: piles are common, but bleeding can have other causes, so have it checked
- Tell the doctor about any diabetes, blood thinners, or a change in your bowel habit
Tests your doctor may order
- Examination of the area, sometimes under anaesthesia if it is too painful
- A short camera test of the back passage (proctoscopy)
- An MRI scan for a complex fistula, or a colonoscopy if there is bleeding that needs a full check
When is surgery needed?
- An abscess is drained by a small cut. Antibiotics alone usually do not clear it.
- A fistula usually needs an operation, and the surgeon chooses the technique that protects bowel control.
- Piles and fissures are treated with simple measures first. Surgery is for those that keep bleeding or hurting.
Related operation guides
Questions people ask
Can an anal abscess heal with antibiotics alone?
Usually not. The pus has to be drained. Antibiotics may be added, but they rarely clear an abscess on their own.
Will I get a fistula after an abscess?
About 1 in 3 people or fewer develop a fistula after an abscess. Your surgeon will explain how to spot it.
Are piles dangerous?
Piles are common and usually not dangerous. But bleeding from the back passage should always be checked by a doctor, in case it has another cause.
Does warm bathing really help?
Yes. Sitting in a warm bath 2–3 times a day eases the pain and helps healing.
This page gives general information and does not replace the advice of your treating team. In an emergency, go to the nearest emergency room.