Perianal abscess drainage procedure

At a glance

Perianal abscess drainage is one of the most common emergency procedures in colorectal surgery. An abscess — a collection of pus near the anus — causes significant pain and will not resolve on its own in most cases. Drainage is the treatment: the pus is released, the pressure drops, and healing can begin.

This guide covers what the procedure involves, what to expect before and after, and how recovery works at home.

Before the procedure

How you get there

Most people arrive at the hospital either through A&E (if the abscess has developed urgently) or through a referral from their GP. The assessment typically includes:

• Examination — the doctor will look at and feel the area to assess the size and location of the abscess
• Decision about anaesthesia — smaller, superficial abscesses can sometimes be drained under local anaesthetic. Larger or deeper ones, or those in people who are very anxious or in severe pain, are drained under general anaesthetic.
• Brief discussion about what the procedure involves and what to expect

What you can do to prepare

If you have any notice (some people are scheduled for drainage rather than arriving emergently):

• Arrange someone to drive you home
• Wear loose, comfortable clothing
• Have stool softeners, gauze, and comfortable underwear ready at home
• Follow any fasting instructions if general anaesthesia is planned

The procedure itself

Under local anaesthetic

1. The area around the abscess is cleaned
2. Local anaesthetic is injected around the abscess — this stings briefly but then numbs the area
3. A small incision is made over the abscess
4. The pus drains out — people describe immediate pressure relief
5. The cavity may be flushed with saline to remove residual material
6. The wound is left open (not stitched) to allow continued drainage
7. Packing may be placed inside the wound

Under general anaesthetic

1. You are put to sleep under general anaesthesia
2. The surgeon examines the area more thoroughly — this sometimes includes checking for a fistula
3. The incision, drainage, and wound management are the same
4. You wake up in recovery with the procedure complete
5. Most people go home once the anaesthesia has worn off

Immediately after

The most common experience people describe is relief. The pressure that had been building — sometimes for days — is gone. The area is sore from the procedure, but the deep throbbing pain of the abscess is dramatically reduced.

You will have:

• A wound that is left open and may be packed with gauze
• Instructions for wound care and when to return for packing changes
• Pain medication — usually paracetamol and ibuprofen, sometimes something stronger
• Advice about sitz baths and hygiene
• A follow-up appointment or referral for ongoing wound care

Recovery at home

The first few days

• Pain management — the procedural soreness typically peaks on day one or two and then improves. Prescribed pain medication helps.
• Sitz baths — warm water after bowel movements and at least once or twice more per day. This keeps the area clean and promotes healing.
• Gauze and packing — wound packing is typically changed by a district nurse every one to three days. Between changes, keeping the area clean and dry is the priority.
• Rest — limited activity for the first few days. Light walking is fine; strenuous activity is not.
• Stool management — soft stools are essential. Stool softeners and fibre should be started immediately if not already in use.

The following weeks

• Packing is gradually reduced and eventually stopped as the wound heals from the inside out
• The wound shrinks progressively
• Discharge decreases over time
• Activity levels can increase gradually
• Follow-up appointments monitor healing and check for fistula formation

How long it takes

Healing time depends on the size and depth of the abscess:

• Small abscesses: two to four weeks
• Medium abscesses: four to eight weeks
• Large or deep abscesses: eight to twelve weeks or longer

These are general ranges. Some people heal faster, some slower. The wound healing is from the inside out, which is slower than a sutured wound but produces a more thorough result.

What to watch for

During recovery, contact your surgical team or GP if you notice:

• Increasing pain — pain should gradually improve, not worsen
• Fever or feeling unwell — could indicate residual or new infection
• Increasing redness or swelling around the wound
• The wound stops draining but the area becomes swollen again — could indicate the wound has closed over too quickly with pus still inside
• Foul-smelling discharge that is new or worsening

The fistula question

One of the most common concerns after abscess drainage is whether a fistula will develop. A fistula — an abnormal tunnel between the inside of the anal canal and the skin surface — develops in roughly one in three to one in two cases of perianal abscess.

Your surgical team will monitor for this during follow-up. Not every abscess leads to a fistula, but it is common enough that follow-up matters. If a fistula does develop, it is a separate condition with its own treatment options.