An anal fissure is a small tear in the lining of the anal canal, the opening where stool exits the body. This common condition typically results from trauma caused by passing hard or large stools, or from chronic diarrhea. Symptoms include sharp, severe pain during a bowel movement, often persisting for hours, and bright red blood on the toilet paper or stool. The pain triggers a spasm in the internal anal sphincter muscle, which restricts blood flow and prevents the tear from healing, creating a painful cycle.
Initial Steps in Diagnosis and Care
The first medical professional a person usually consults for symptoms like anal pain and bleeding is a Primary Care Physician (PCP) or General Practitioner (GP). The PCP’s role is to provide an initial diagnosis, often through a gentle visual inspection of the anal area, as a full digital rectal exam can be too painful. The physician will also attempt to rule out other common causes of rectal bleeding and pain, such as hemorrhoids.
This initial consultation focuses on conservative treatments designed to alleviate symptoms and promote healing for most acute fissures. These treatments include prescribing stool softeners or fiber supplements to ensure easy passage of bowel movements. They also recommend warm sitz baths to help relax the anal sphincter muscle. If the fissure does not begin to heal after about a week of these measures, or if the symptoms are severe, the PCP will consider prescribing topical medications or referring the patient to a specialist.
Who Are the Specialists
If conservative care fails to heal the fissure within four to eight weeks, or if the diagnosis is uncertain, a referral to a specialist becomes necessary. The two primary specialists involved in advanced anal fissure care are the Gastroenterologist and the Colorectal Surgeon. The Colorectal Surgeon specializes in conditions affecting the colon, rectum, and anus, including surgical management.
A Gastroenterologist specializes in medical treatment for disorders of the entire digestive tract. Their expertise is useful for diagnostic testing, such as a sigmoidoscopy or colonoscopy, which may be needed to ensure the fissure is not a symptom of an underlying condition like Crohn’s disease or other inflammatory bowel issues. While they primarily manage non-surgical cases, they are skilled in prescribing and administering advanced non-surgical treatments, such as Botulinum Toxin injections.
Non-Surgical Treatment Pathways
For fissures that do not respond to initial measures, the next step involves topical medications aimed at reducing the resting pressure of the internal anal sphincter. This involuntary muscle spasm is the main reason chronic fissures fail to heal, as it reduces blood flow to the area. Topical nitroglycerin ointment, typically a 0.2% concentration, works by releasing nitric oxide, which is a potent relaxant for the smooth muscle of the sphincter and increases blood flow to the tear.
Other common topical agents are calcium channel blockers, such as nifedipine or diltiazem, often compounded into an ointment. These medications also relax the internal sphincter muscle, with studies suggesting that they may be associated with fewer side effects than nitroglycerin, which can cause severe headaches. If topical treatments fail, a highly targeted treatment is the injection of Botulinum Toxin (Botox) directly into the internal anal sphincter. This neurotoxin temporarily paralyzes the muscle, achieving a chemical sphincterotomy that reduces pressure and allows the fissure to heal, with reported success rates in some studies reaching up to 85%.
Advanced Procedures for Chronic Fissures
When all non-surgical methods, including topical therapies and Botulinum Toxin injections, have failed to heal a chronic fissure after several weeks of treatment, a Colorectal Surgeon may recommend a surgical procedure. The standard operation for chronic anal fissures is the Lateral Internal Sphincterotomy (LIS). This procedure involves making a small incision to cut a controlled portion of the internal anal sphincter muscle.
The primary goal of the LIS is to reduce the excessive resting pressure within the anal canal by 20% to 50%, which then allows for increased blood flow and promotes healing of the tear. The procedure has a high rate of success, with healing achieved in 90% to 96% of cases, and it provides immediate pain relief. While LIS is highly effective, it is reserved as a last resort because there is a small risk of developing temporary or permanent fecal incontinence.