An anal fissure is a small, linear tear in the thin lining of the anal canal. This condition causes significant discomfort, often presenting as sharp pain during a bowel movement, followed by a deep, burning sensation that can persist for several hours. Small amounts of bright red blood may also be visible. Fissures develop when hard or large stools stretch the anal mucosa, creating a tear that causes the internal anal sphincter muscle to spasm. This spasm reduces blood flow, preventing healing and creating a cycle of pain. Most fissures can be successfully treated with non-surgical interventions, but readers should consult a healthcare professional for an accurate diagnosis and personalized treatment plan.
Initial At-Home Strategies for Healing
The primary step in treating an anal fissure involves softening the stool to prevent further trauma. This is achieved by significantly increasing dietary fiber intake and daily fluid consumption. Fiber adds bulk to the stool, helping it retain water, with the goal of reaching 25 to 35 grams per day through foods like whole grains, fruits, and vegetables. Consistent hydration allows the fiber to work effectively and keeps the stool soft, minimizing strain during defecation.
Incorporating warm water soaks, known as sitz baths, provides immediate symptom relief and promotes healing. Soaking the anal area in warm water for 10 to 20 minutes, two to three times daily and especially after a bowel movement, serves a dual purpose. The warmth soothes nerves and relaxes the spastic internal anal sphincter muscle, easing pain. This relaxation also increases blood circulation to the tear, accelerating tissue repair.
Gentle hygiene practices are necessary to avoid irritation. Using soft, unscented wipes or a bidet to clean the area after a bowel movement is preferable to using dry toilet paper. Avoid vigorous rubbing or scrubbing; gently pat the area dry to prevent further damage. Over-the-counter stool softeners can be used temporarily if dietary changes alone are not immediately effective.
Targeted Medical Ointments and Prescriptions
When conservative measures fail, prescription topical medications are used to relax the spastic internal anal sphincter. The goal of these ointments is to reduce pressure within the anal canal, improving blood flow to the tear and facilitating tissue repair by chemically relaxing the sphincter’s smooth muscle fibers.
One common prescription is nitroglycerin ointment (0.2% to 0.5%), a nitric oxide donor. Nitric oxide is a potent vasodilator that causes the sphincter muscle to relax, lowering anal pressure and enhancing circulation. A recognized side effect is headache, which sometimes leads patients to discontinue use.
Alternatively, topical calcium channel blockers, such as diltiazem (2% cream) or nifedipine (0.2% to 0.5% ointment), are often prescribed. These medications achieve muscle relaxation by blocking calcium entry into the sphincter’s smooth muscle cells. Calcium channel blockers are associated with a lower incidence of systemic side effects than nitroglycerin. These ointments are typically applied directly for several weeks, often combined with continued high-fiber and hydration regimens.
Procedures for Non-Healing Fissures
If a fissure fails to heal after approximately eight weeks of conservative and pharmacological treatment, it is classified as chronic and may require advanced medical procedures. These interventions focus on achieving deeper, longer-lasting relaxation of the internal anal sphincter muscle.
Botulinum Toxin Injection
One minimally invasive option is an injection of Botulinum toxin (Botox) directly into the internal sphincter. The toxin temporarily paralyzes a portion of the muscle, relieving the chronic spasm that prevents healing. This chemical relaxation typically lasts for two to three months, allowing the fissure to fully heal. This technique boasts a high success rate, often exceeding 80%, and carries a low risk of permanent complications since the paralysis is temporary.
Lateral Internal Sphincterotomy (LIS)
For chronic cases that do not respond to injections, a surgical procedure called a Lateral Internal Sphincterotomy (LIS) is the most definitive treatment. This operation involves making a small, controlled cut in the internal anal sphincter muscle, permanently reducing resting pressure. LIS has a success rate of over 90% and directly addresses muscle hypertonia. While LIS is the gold standard, it carries a small but permanent risk of affecting continence, specifically the ability to control gas or liquid stool. The choice between Botox and LIS depends on the fissure’s chronicity and the surgeon’s assessment of risk.
Maintaining Bowel Health to Avoid Relapse
After the fissure has healed, the focus must shift to long-term prevention, as fissures tend to recur. Sustained high-fiber intake (25 to 35 grams daily) must become a permanent dietary habit to ensure stools remain soft and bulky. This must be paired with consistent, adequate fluid intake, typically eight or more glasses of water a day, to prevent stools from hardening.
Establishing a regular bowel habit that avoids straining is paramount for preventing future tearing. This includes responding promptly to the urge to defecate and avoiding prolonged sitting on the toilet, which increases anal pressure. Incorporating regular, moderate physical activity also helps stimulate normal bowel function and promotes overall digestive health. Patients should maintain follow-up care with their physician if they experience any return of pain or bleeding. This monitoring helps ensure underlying conditions, such as chronic constipation, are managed effectively.