An anal fissure is a small tear in the lining of the anal canal that causes sharp pain and bright red bleeding when passing stool. Most heal with simple home care, including more fibre, plenty of water and warm sitz baths. When a fissure becomes chronic, ointments or a minor operation heal it effectively.
An anal fissure is a small tear in the thin, sensitive lining of the anal canal, the last short section of the back passage. Although the tear itself is tiny, often no bigger than a paper cut, it can cause a sharp, burning pain that feels completely out of proportion to its size, particularly during and just after passing a stool. Anal fissures are extremely common, affect people of every age including infants and older adults, and are one of the reasons many people quietly endure discomfort for far longer than they need to before seeking help. The encouraging news is that most fissures are not serious and heal with simple, gentle measures, and there is no need to feel embarrassed, because a fissure is one of the most common and most treatable problems that a proctology clinic sees. This guide explains what causes them, how to care for one at home, the treatments available when healing is slow, and the warning signs that mean you should be checked. You can also read more on our anal fissure information page.
What is an anal fissure?
An anal fissure is a small split or tear in the lining of the anal canal, the last part of the bowel through which stool passes. It is often described as looking like a paper cut. Fissures are called acute when they are recent and heal quickly, and chronic when they persist beyond roughly six to eight weeks.
What causes anal fissures?
Most anal fissures are caused by trauma to the delicate anal lining, usually from passing a hard, large, or forced stool. Constipation is the most common trigger, but ongoing diarrhoea, repeated straining, and childbirth can also be responsible. Once a tear forms, the nearby muscle tends to go into spasm, which reduces blood flow and makes natural healing more difficult.
- Constipation and the passing of hard, dry, or unusually large stools
- Straining on the toilet or sitting there for long periods
- Repeated or long-lasting episodes of diarrhoea
- Childbirth, especially after a difficult or prolonged delivery
- A tight or overactive internal anal sphincter muscle
- Reduced blood supply to the back part of the anal canal
- Less often, inflammatory bowel disease, infections, or previous anal surgery
What are the symptoms of an anal fissure?
The most typical symptom is a sharp, burning, or tearing pain during a bowel movement, often followed by a deeper ache or muscle spasm that can linger from a few minutes to several hours afterwards. Many people also see a small streak of bright red blood on the stool, on the toilet paper, or in the bowl.
Because the pain can be intense, a fissure often sets up a difficult cycle: the discomfort makes people afraid to open their bowels, so they hold on, the stool becomes harder and larger, and the next bowel movement tears the lining again. Understanding this cycle is the key to breaking it, because most treatment is aimed at keeping the stool soft and comfortable so the tear is given a chance to heal. Alongside pain and bleeding, some people notice itching or irritation around the anus, a small skin tag near the fissure if it has become chronic, or a sensation of spasm. It is important to know that bright red bleeding, while very commonly caused by something harmless like a fissure or piles, should never simply be assumed to be minor. Darker blood, blood mixed through the stool, a change in your usual bowel habit, unexplained weight loss, or bleeding in anyone over the age of forty deserves a proper medical assessment to rule out other conditions. Diagnosis is usually straightforward: a doctor can often identify a fissure with a gentle examination of the area, and because the region is tender, an experienced clinician will be careful and considerate, sometimes using a little local anaesthetic gel to make the examination comfortable. A more detailed internal examination is not always needed at the first visit and can be deferred until the pain has settled. If you are unsure what is causing your symptoms, or if they are not settling, it is always safer to be examined than to keep guessing at home. You can learn more about the condition and how it is diagnosed on our anal fissure page.
How can you treat an anal fissure at home?
Most acute anal fissures heal with simple self-care aimed at softening the stool and easing muscle spasm. The cornerstones are eating more fibre, drinking plenty of water, and avoiding straining. Warm sitz baths, which means sitting in a few inches of warm water for ten to fifteen minutes, especially after a bowel movement, relax the muscle and soothe the area.
- Gradually increase the fibre in your diet with fruit, vegetables, and wholegrains
- Drink plenty of water through the day to keep stools soft
- Consider a fibre supplement or a gentle stool softener if your doctor agrees
- Take warm sitz baths for ten to fifteen minutes, especially after passing a stool
- Do not delay or hold in a bowel movement when you feel the urge
- Avoid straining and try not to sit on the toilet for long periods
- Keep the area clean and gently patted dry, avoiding harsh soaps or vigorous wiping
- Stay physically active, as regular movement helps the bowel work normally
What medical and surgical treatments are available?
If a fissure does not heal with self-care, doctors can prescribe medicated ointments that relax the anal muscle and improve blood flow so the tear can heal. When a chronic fissure resists these measures, a minor procedure to relax the tight sphincter muscle is highly effective. Your surgeon will explain which option best suits your situation.
Prescription treatments usually come first. Ointments containing a nitrate or a calcium-channel blocker are applied to relax the internal sphincter and boost the blood supply that healing depends on; a temporary headache is a common side effect of the nitrate creams. In some cases an injection of botulinum toxin is used to relax the muscle for a period long enough to allow the fissure to heal. When a chronic fissure fails to settle despite these efforts, surgery is considered, and the results are generally very good. The traditional and highly effective operation is a lateral internal sphincterotomy, in which a tiny portion of the tight internal muscle is divided to release the spasm and restore blood flow, allowing the tear to heal. It is a small, quick procedure, usually done as a day case. Most people notice that the intense, spasm-related pain eases quickly afterwards, and the fissure itself then heals over the following weeks. For anyone thought to be at higher risk of continence problems, a surgeon may prefer to persist with ointments or use a botulinum toxin injection rather than dividing any muscle, so the plan is always matched carefully to the individual. Your surgeon will discuss the benefits and the small risks with you honestly, including the uncommon possibility of minor changes in control of wind, so that you can make an informed choice. The right treatment depends on how long you have had the fissure, how severe it is, and your general health. It is worth knowing that surgery is only considered once simpler measures have had a fair trial, and even then it is usually a small day-case procedure with a quick recovery, so it should not be a source of fear. Many people who have struggled with the sharp, recurring pain of a chronic fissure for months find that the right treatment brings lasting relief and lets them return to a normal, comfortable routine. If home measures have not worked, or if the pain is affecting your daily life, sleep, or ability to work, it is worth arranging a proper assessment rather than continuing to suffer. You can book a consultation to discuss your options in confidence.
How can you prevent anal fissures from coming back?
Preventing a fissure from returning comes down to keeping your stools soft and your bowel habits comfortable for the long term. A high-fibre diet, good hydration, regular exercise, and responding promptly to the urge to go all reduce the straining that tears the anal lining. These same habits also lower the risk of related problems such as piles.
Because fissures are so closely linked to constipation and straining, the most reliable way to stop them recurring is to make soft, regular bowel movements a permanent part of your routine rather than a short-term fix. Aim to build fibre into your meals every day, drink enough fluid that you rarely feel thirsty, and keep moving with regular walking or other activity, all of which help the bowel work smoothly. When increasing fibre, do so gradually and with plenty of water, since a sudden large jump can cause bloating and wind; the aim is a soft, formed stool that passes without effort, not loose or urgent stools. It is also wise not to rely on strong stimulant laxatives over the long term without medical advice, as the bowel can become dependent on them. Try not to rush or strain on the toilet, avoid spending long stretches sitting there reading or using your phone, and go when your body tells you to rather than putting it off. If you are prone to constipation despite these steps, speak to your doctor about whether a regular fibre supplement or stool softener would help. Treating any tendency to constipation early, and dealing with bouts of diarrhoea sensibly, protects the delicate anal lining from repeated injury. Most people who adopt these habits find that fissures stop troubling them. It also helps to be gentle with the area in daily life: avoid harsh, perfumed soaps and rough toilet paper, pat rather than rub after washing, and treat any itching or irritation early before scratching damages the skin. For new mothers, whose fissures often follow childbirth and constipation in the postnatal period, the same soft-stool measures are especially valuable while the body recovers. If you have had more than one fissure, or if the problem keeps returning despite your best efforts, an assessment can check for any underlying cause, such as a persistently tight sphincter or an inflammatory condition, and make sure nothing else is being missed. You are welcome to book an appointment for tailored advice.
This article offers general educational information only and is not a substitute for a professional medical consultation. Anal symptoms are common and usually treatable, but they can occasionally point to something that needs closer attention, so persistent or worrying symptoms should always be checked in person. If a fissure is not healing, or the pain and bleeding are affecting your life, please book an appointment with Dr. Sujan Shrestha for a careful, confidential assessment.