The anal canal is a short tube surrounded by muscle at the end of your rectum. The rectum is the bottom section of your colon (large intestine). An anal fissure (also called fissure-in-ano) is a small rip or tear in the lining of the anal canal. Fissures are common but are often confused with other anal conditions, such as hemorrhoids.
Fissures are usually caused by trauma to the inner lining of the anus from a bowel movement or other stretching of the anal canal. This can be due to a hard, dry bowel movement or loose, frequent bowel movements. Patients with a tight anal sphincter muscle are more likely to develop anal fissures. Less common causes of fissures include Inflammatory Bowel Disease, anal infections, or tumors.
Anal fissures typically cause a sharp pain that begins with the passage of stool. This pain may last several minutes to a few hours. As a result, many patients may try not to have bowel movements to prevent pain.
Other symptoms include:
- Bright red blood on the stool or toilet paper after a bowel movement
- A small lump or skin tag on the skin near the anal fissure (more common when chronic)
Your physician will discuss the benefits and side effects of treatments.
- A high-fiber diet and over-the-counter fiber supplements (25-35 grams of fiber/day) to make stools soft, formed, and bulky.
- Over-the-counter stool softeners to make stools easier to pass.
- Drinking more water to help prevent hard stools and aid in healing.
- Warm tub baths (sitz baths) for 10-20 minutes, a few times per day (especially after bowel movements to soothe the area and help relax anal sphincter muscles). This is thought to help the healing process.
- Medications, such as lidocaine, that can be applied to the skin around the anus for pain relief.
- Medications such as diltiazam, nifedipine, or nitroglycerin ointment to relax the anal sphincter muscles help the healing process.
- Narcotic pain medications are avoided because they can cause constipation, which could make the situation worse.
Although most anal fissures do not require surgery, chronic fissures are harder to treat and surgery may be the best option. The goal of surgery is to help the anal sphincter muscle relax, which reduces pain and spasms, allowing the fissure to heal. Surgical options include Botulinum toxin (Botox®) injection into the anal sphincter or surgical division of an inner part of the anal sphincter (lateral internal sphincterotomy). Your colon and rectal surgeon will find the best treatment for you and discuss the risks of surgery. Both types of surgery are typically done as same-day, outpatient procedures.
Most patients can return to work and their daily activities a few days after surgery. Complete healing after both medical and surgical treatments can take 6-10 weeks. Even when the pain and bleeding lessen, it is important to maintain good bowel habits and eat a high-fiber diet. Continued hard or loose bowel movements, scarring, or spasm of the internal anal muscle can delay healing.
- Botox® injections are associated with the healing of chronic anal fissures in 50%-80% of patients.
- Sphincterotomy is successful in more than 90% of patients. Although uncommon, this procedure may affect the patient’s ability to fully control gas or bowel movements.
- Fissures often come back. A fully healed fissure can come back after a hard bowel movement or trauma. Medical problems such as Inflammatory Bowel Disease (Crohn’s Disease), infections, or anal tumors can cause symptoms similar to anal fissures. If a fissure does not improve with treatment, it is important to be evaluated for other possible conditions.
Can anal fissures lead to colon cancer?
Anal fissures do not increase the risk of colon cancer nor cause it. However, more serious conditions can cause similar symptoms. Even when a fissure has healed completely, your colon and rectal surgeon may request other tests. A colonoscopy may be done to rule out other causes of rectal bleeding.