Treatment of anal fissure is aimed at breaking the cycle of pain and spasm so healing can take place. Non surgical management include avoidance of constipation and topical analgesia. Other topical ointment that aims to relax the anal sphincter is often prescribed first before surgical treatment is considered.
If surgical treatment is considered, there are 2 main options: injection of Botox or lateral sphincterotomy.
Both procedures aims to relax the anal sphincter muscles so healing of the mucosa can occur. Lateral sphincterotomy involves cutting the internal sphincter of the anal canal and remains the gold standard treatment for chronic anal fissure. This is often done in a modified way which means the internal sphincter is only cut the same length as the fissure itself. Although only a very small segment of the internal sphincter is cut, there is still a very low risk of incontinence, usually temporary. Most often, it only involves incontinence of gas, which means an inability to hold on to flatulence. Rarely does incontinence becomes an issue long term.
Injection of botulinum toxin (Botox) into the anal sphincter has a similar effect to cutting the internal sphincter. By injecting Botox into the space between internal and external sphincter, it helps the sphincter muscle relax, allowing the fissure to heal. There is still a very small risk of incontinence but due to the temporary nature of the toxin, the complication of incontinence is also temporary. By the time the effect of the toxin has worn off, it would have allowed adequate time for the fissure to heal.