What is an anal fissure?
Patient information: Anal fissure [American College of Colon and Rectal Surgeons]
Patient education: Anal fissure (Beyond the Basics) [UpToDate]
Trauma from hard stool (constipation) creates a tear in the anoderm distal to the dentate line. Pain leads to internal sphincter spasm, setting up a vicious cycle!
Symptoms- severe pain during and immediately following a bowel movement ("like pooping glass", "passing a razor blade"), blood on toilet paper with wiping. This often leads to fear of having bowel movements. Pain leads to muscle spasm→ higher pressure→ vicious cycle.
Diagnosis- classic history is almost enough, but pain with effacement of the buttocks and visualization of a tear in the anoderm confirms. Don’t torture them with a digital rectal exam! On exam, typically seen in the posterior midline. If a fissure is seen in a different location, consider IBD, trauma, infection (Tuberculosis, sexually transmitted diseases), cancer.
Source: UpToDate Images: Anal Fissure Anatomy
What is conservative management for an anal fissure?
See “Anorectal Disease: How do I prevent anorectal disease?” Improving bowel habits is the first-line treatment for an anal fissure.
See patient handouts below.
The majority of patients with an acute fissure heal with conservative management. If a fissure has been present for a long time, it is less likely to heal with conservative therapy.
Sitz baths- fill a tube with water as warm as you can tolerate, and soak your bottom after every bowel movement and at least 3 times per day.
Topical compounds- nitrates, calcium channel blockers→ relax muscle→ improved blood flow→ allows healing. Local anesthetics can also improve symptoms during the healing process.
Avoid suppositories, Tucks pads, and Preparation H. These would be painful and won’t treat the disease. This is why diagnosis is vital.
What is the operative management for an anal fissure?
For the few patients who fail a trial of conservative therapy, surgical intervention can provide relief.
Botulinum toxin (Botox) blocks neuromuscular function leading to muscle relaxation. Yes, this is the same Botox that is used to treat wrinkles. Low risk of complications.
Lateral internal sphincterotomy is the treatment of choice for chronic fissures that have failed to resolve with other interventions. More successful healing compared to other interventions. Risk of incontinence (inability to control the passage of gas and stool). If incontinence occurs, the inability to control gas is more common than the inability to control liquid stool, which is more common than the inability to control solid stool.