Why an anal fissure hurts so much, and why it keeps reopening

An anal fissure is a small tear in the lining of the anal canal. It is tiny, and it produces pain out of all proportion to its size. The reason it does not heal is a spasm cycle, and understanding that cycle is what makes the treatment make sense.

Patients describe it consistently: a sharp cutting pain on passing stool, like glass, followed by a deep burning ache that can last an hour or several. There is often a small amount of bright red blood on the paper. Many people assume it is piles, but piles are usually painless. Sharp pain with bleeding points to a fissure.

The cycle that stops it healing

A hard or forced stool tears the lining. The tear exposes the internal sphincter muscle underneath, and that muscle responds by going into spasm. Spasm does two things: it hurts, and it squeezes shut the small blood vessels that supply the area.

A wound with a poor blood supply cannot heal. So the tear stays open, the next stool reopens it, and the spasm tightens further. This is why a fissure that is a few weeks old behaves completely differently from one that is a few days old, and why willpower and creams from the pharmacy so often fail.

There is a second trap. Because opening the bowels hurts, people start avoiding it. The stool sits longer, dries out, becomes harder, and does more damage when it finally passes. Almost every long-standing fissure has this pattern somewhere in its history.

Acute or chronic, and why it matters

A fissure under about six weeks old is called acute. It looks like a fresh tear and a majority heal with conservative treatment alone. Beyond six weeks it becomes chronic: the edges thicken, a skin tag often forms at the outer end, and the exposed muscle fibres become visible. Chronic fissures heal far less reliably without addressing the spasm directly.

That six-week mark is the reason not to wait it out indefinitely. The window where simple measures work well is early.

What to try first

• Soften the stool properly. Fibre, water, and a stool softener taken consistently rather than occasionally. In Dubai’s climate most people are mildly dehydrated, which matters more than they think.
• Warm baths for ten minutes, two or three times a day. This is not folklore; warmth genuinely relaxes the sphincter.
• Do not sit and strain. Do not take a phone to the toilet.
• Prescribed ointments that relax the muscle, such as topical nitrate or calcium-channel-blocker preparations, address the spasm rather than just the pain. Headaches are a common side effect of the nitrate ones.

When creams are not enough

If a chronic fissure has not healed after a proper trial of medical treatment, the spasm has to be released. Traditionally that means lateral internal sphincterotomy: dividing a small portion of the internal sphincter. It has a high success rate and a long track record, and it carries a small but real risk to continence, which is why the decision is not taken lightly.

Controlled laser sphincterotomy aims at the same target with a more measured release, and can be combined with laser treatment of the fissure edges to encourage healing. The fissure treatment page sets out how it is done and what the trade-offs are.

When it is not a simple fissure

Fissures away from the midline, multiple fissures, or ones that will not settle despite everything should prompt a look for another cause, including inflammatory bowel disease. A fissure that keeps recurring after a technically good operation deserves that question rather than another operation.

Dr Kerim Erdem Ulucay is a DHA-licensed Specialist General and Laparoscopic Surgeon and a certified laser proctologist, consulting in Jumeirah 1 and JLT. If the pain has lasted more than six weeks, or you are avoiding the toilet, message +971 55 558 4957 or use the contact page.

General information, not a diagnosis. Anal pain and bleeding should be assessed in person.