Anal fissures usually heal within a few weeks and do not require medical treatment. However, they may recur easily if it was caused by constipation which remains untreated. However, in other cases the symptoms may persist for six weeks or more, in which case they are referred to as a chronic anal fissure. These will probably require medical treatment in order to heal.
Non-surgical medical treatments options to treat an anal fissure include medications prescribed by your doctor.
Surgical procedure for anal fissure:
A surgery may be recommendable in cases of a severe pain due to anal fissure, or when the symptoms of an anal fissure are persistent and do not heal with other forms of treatment. The surgery to correct an anal fissure is called a lateral internal sphincterotomy.
During the procedure, a thin portion of muscle for your anal sphincter is divided in order to help your wound heal faster.