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 several 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 health professional 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 usually needs additional treatment.

Medication

Medications are usually the first-line treatment for chronic fissures.

• A 0.2% nitroglycerin cream can relax 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 medication can cause headaches, lightheadedness, or fainting from low blood pressure.
• The calcium channel blockers nifedipine and diltiazem also may help healing. These two medicines are available as pills. Nifedipine is also available as an ointment, but diltiazem is not yet available as an ointment in the United States. A study has shown that an ointment containing nifedipine and lidocaine can help the healing of chronic anal fissures without any significant side effects.³
• Botulinum toxin (Botox) may be injected into the internal anal sphincter. Botox causes temporary paralysis of muscle, which can reduce muscle tension and promote healing.

Surgery

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 health professional makes a small incision into the internal anal sphincter to reduce anal resting pressure. After surgery, about 8% of people have long-term complications.⁴ Some people have short-term problems such as pain, bleeding, or temporary inability to control gas (gas incontinence) or stool. Yet patient satisfaction with the surgery is high.⁵

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.

In some cases the risk of incontinence is too great to justify doing lateral internal sphincterotomy. This may be true for women who develop a fissure while giving birth, because they typically do not have a high resting pressure in their internal sphincter. A procedure called anal advancement flap may be done instead of sphincterotomy.¹ In this procedure, the edges of the fissure are removed, and healthy tissue is sewn over the area.