Most short-term (acute) anal fissures can heal with home treatment in 4 to 6 weeks. Pain during bowel movements usually goes away within a couple of days of treatment.
Home treatment involves sitting in warm water (sitz bath) for 20 minutes 2 or 3 times a day, increasing fiber and fluids in the diet, and using stool softeners or laxatives to have pain-free bowel movements. Talk with your doctor about how long you should use laxatives.
Sometimes fissures do not heal with these remedies. A fissure that has not healed after 6 weeks is considered long-term, or chronic, and may need additional treatment.
Medicines are usually the first-line treatment for chronic fissures.
A 0.2% nitroglycerin cream can reduce the pressure in the internal anal muscle (sphincter) and allow the fissure to heal. A pea-sized dot of cream is massaged into the fissure and the surrounding area. Do not use a larger amount at one time, because this medicine can cause headaches, lightheadedness, or fainting from low blood pressure. It is a good idea to either wear gloves when applying the nitroglycerin cream or wash your hands right after. The skin on your fingers can absorb the medicine and increase your chance of side effects.
The calcium channel blockers nifedipine and diltiazem also may help healing, also by reducing the pressure in the internal anal sphincter. These two medicines are available as pills. Also, they can be made into a gel that can be massaged into the fissure and the surrounding area. The pill form of these medicines has more side effects than the gel form.
Botulinum toxin (Botox) may be injected into the internal anal sphincter. Botox causes temporary paralysis of muscle, which can reduce muscle tension and help the anal fissure heal.
Surgery may be done when more conservative treatments fail to heal an anal fissure.
The main surgery for chronic anal fissure is lateral internal sphincterotomy. The doctor makes a small incision into the internal anal sphincter to reduce anal resting pressure.
It is important to understand that, even with surgery, an anal fissure must heal on its own. A sphincterotomy involves operating on the sphincter muscles, not closing the actual fissure.
Lateral internal sphincterotomy has a better success rate than any medicine that is used to treat long-term anal fissures. The results last longer, and fewer people have anal fissures come back after surgery than after treatment with medicine.
In some studies, a greater number of people who had lateral internal sphincterotomy had some inability to control gas or stool (incontinence) after surgery compared to people treated with medicine. Despite these results, satisfaction with this surgery is high. And a review of many studies showed that the risk of incontinence was 8%. This means that about 8 out of 100 people who had the surgery had some problem with incontinence. But this rate was not very different from the rates seen in people who were treated with medicine for their chronic anal fissures.