Why does an anal fissure hurt for hours after a bowel movement?

Why does the pain last so long after the bowel movement?

Patients often describe two different pains. The first is a cutting pain, like passing glass, while the stool goes through. The second starts a few minutes later and is a burning, throbbing or cramping pain that can last from 20 minutes to several hours. Some people lose the whole morning to it. That second pain is the one that confuses people, because by then the stool is long gone.

The explanation is the internal anal sphincter, a ring of muscle under the fissure that you cannot control at will. When the stool stretches the tear, the sphincter reacts with a strong contraction, a spasm. A muscle in spasm hurts in itself, the way a calf cramp hurts. It also squeezes the small vessels that feed the back of the anal canal, so the tear receives less blood, which keeps the area painful and slows healing. The longer the spasm lasts, the longer the pain lasts.

This also explains why fear of the bathroom takes hold so easily in people with a fissure. When each bowel movement costs hours of pain, holding in seems logical, but it makes the next stool harder and the next tear worse. We discuss that loop in All guides.

How long is the pain normal, and how does it differ from hemorrhoids?

In a typical fissure the pattern is predictable: sharp pain with the bowel movement, a lingering burning or cramping pain for minutes to hours, then relative calm until the next one. A small amount of bright red blood on the paper is common. Pain that follows this rhythm, and that slowly lessens over the days, fits a fissure.

The clearest difference is that hemorrhoids rarely hurt after the bowel movement unless a clot forms, and a clotted hemorrhoid hurts all the time, not in waves after each stool. For the full comparison, read Fissure or hemorrhoids? The pain rule that tells them apart, and for a structured self-check, Anal fissure symptoms: a 2-minute self-check.

What relieves the pain right after a bowel movement?

The goal after each bowel movement is to relax the sphincter and protect the tear. In order of usefulness:

• A warm sitz bath. Sit in 5 to 10 centimeters of comfortably warm water (not hot) for 10 to 15 minutes, right after the stool. Warm water relaxes the internal sphincter and cleans the area without rubbing. This is the most effective home measure for spasm pain. Our guide on All guides covers temperature, timing and common mistakes.
• Gentle cleaning. Rinse with water or use soft, unscented wipes, and pat dry. Repeated wiping with dry paper reopens the tear.
• Your ointment, after the bath. If you have a prescribed sphincter-relaxing ointment, the post-bowel-movement application is one of the most important of the day.
• Lie down if you can. Sitting upright on a hard chair keeps pressure on the area; lying on your side for a while helps some people while the spasm settles.

Two things to avoid: very hot water, which irritates the skin, and sitting on the toilet for long periods with your phone, which keeps the canal congested. If the spasm wakes you at night, see All guides.

Which creams treat the spasm, not just the pain?

Here is the key distinction. Anesthetic creams such as lidocaine dull the nerve endings of the tear for an hour or two. Applied 10 to 15 minutes before a bowel movement, they can make it bearable, which helps you stop holding in. But they do not relax the sphincter, so the spasm comes back and the fissure stays open. Our article on Lidocaine cream for anal fissure: why it eases the pain but does not close the tear explains how to use them sensibly.

Sphincter-relaxing ointments act on the cause of the lingering pain. Topical nifedipine and diltiazem are calcium channel blockers; nitroglycerin releases nitric oxide. All three lower the resting pressure of the internal sphincter, which reduces spasm and lets blood back into the tear. They are used two to three times a day for 6 to 8 weeks. Nitroglycerin causes headache in up to half of patients, which is why many surgeons now start with nifedipine or diltiazem.

The evidence supports this approach. In a multicenter study of acute fissures, nifedipine gel 0.2 % led to remission in 95 % at 21 days, compared with 50 % with lidocaine plus hydrocortisone (Antropoli, 1999). The Cochrane review of non-surgical therapy concluded that calcium channel blockers match nitroglycerin in efficacy with fewer adverse effects. Pain usually starts to fall within the first one to two weeks, long before the fissure is fully closed. See our nifedipine page for details.

Avoid relying on hemorrhoid creams or steroid ointments for this pain. They do not relax the sphincter, and hydrocortisone should never be used for more than 7 days.

Can you take painkillers for fissure pain?

For many people, a simple oral painkiller taken on bad days helps them get through the first week while the other measures start working. Ask your doctor or pharmacist which one suits you, especially in these situations:

• Acetaminophen (paracetamol) is usually the first choice and is generally well tolerated at standard doses; check the maximum daily dose and other medicines that may already contain it.
• Anti-inflammatories such as ibuprofen or naproxen can help with the spasm pain, but are not suitable if you have stomach ulcers, kidney disease, certain heart conditions, take blood thinners, or are pregnant.
• Opioids, including codeine and tramadol, are a poor choice for fissure pain. They cause constipation, and a hard stool is the last thing a fissure needs.

If you are pregnant or breastfeeding, have a chronic illness, or need painkillers for more than a few days, talk to your doctor. Needing regular painkillers is itself a sign that the fissure should be properly treated, not just covered up.

How do you make the next bowel movement hurt less?

The pain after a bowel movement is proportional to how much the stool stretches the tear. Soft, formed stools are the most powerful painkiller you have:

1. Fiber, built up gradually: 25 to 30 g a day, ideally with psyllium, plus enough water. Jensen’s randomized study found that 87 % of acute fissures healed at 3 weeks with warm sitz baths plus bran, compared with 60 % with lidocaine ointment alone.
2. A stool softener or osmotic laxative such as polyethylene glycol for the first weeks if your stools are still hard; see All guides.
3. Do not postpone the toilet. Go when you feel the urge; held-in stool becomes harder.
4. Do not strain and do not stay on the toilet longer than needed. A small footstool under your feet straightens the anorectal angle.
5. Numb before, relax after: an anesthetic gel 10 to 15 minutes before, a sitz bath and your relaxing ointment after.

If you are in the first days of a new fissure, All guides puts these steps in order.

When is pain after a bowel movement a warning sign?

Pain that follows the fissure pattern and improves with treatment is expected. Pain that breaks that pattern is not. See a doctor without delay if you notice:

If the pattern makes you think of an abscess or a fistula rather than a fissure, read Fissure, fistula or abscess? How to tell them apart.

Where does FISURIN fit?

FISURIN was designed by our surgeons at Clínica Proctológica de Lima around exactly this pain: it combines nifedipine, which relaxes the internal sphincter and targets the lingering spasm, with lidocaine, which dulls the cutting pain of the bowel movement, in a water-based hydrogel used with a written 6-week protocol. It does not replace soft stools or sitz baths, it does not work in a few hours, and it cannot promise that every fissure will close. A randomized double-blind trial of nifedipine 0.3 % with lidocaine 1.5 % reported healing in 94.5 % of chronic fissures at 6 weeks, against 16.4 % with the control (Perrotti, 2002). Today FISURIN is a magistral formula prepared under prescription in Peru and is not shipped abroad; FISURIN Hydrogel and FISURIN Relief are in preparation, with a waiting list. See what is inside FISURIN or how to get it where you live.