Most anal fissures are not serious. They’re small tears in the lining of the anal canal that cause sharp pain and minor bleeding during bowel movements, and more than 80% of acute fissures heal on their own with basic home care. That said, fissures that don’t heal within several weeks can become a chronic problem that leads to real complications, so they’re worth paying attention to even though they’re rarely dangerous.
With an estimated lifetime incidence of about 11%, anal fissures are one of the most common conditions affecting the anus. They tend to show up most often in young adult women and middle-aged men.
Acute vs. Chronic Fissures
The key distinction is how long the tear persists. A fissure that fails to heal within eight weeks is considered chronic. Acute fissures are essentially fresh wounds that respond well to simple measures like softening your stool and keeping the area clean. Chronic fissures develop scar tissue and deeper changes in the surrounding muscle that make them self-perpetuating: the internal sphincter muscle spasms, which reduces blood flow to the tear, which prevents healing, which causes more spasm.
An acute fissure feels like a paper cut during and after a bowel movement. A chronic fissure causes the same sharp or burning pain, but it tends to linger for hours afterward and often comes with a visible skin tag near the tear. If your symptoms have stuck around for two months or more, you’re likely dealing with a chronic fissure that won’t resolve without more targeted treatment.
What Happens If a Fissure Doesn’t Heal
Left untreated for a long time, chronic fissures can lead to three main complications. The first is fecal impaction, where ongoing pain makes you avoid bowel movements, leading to a buildup of hardened stool. The second is anal stenosis, a narrowing of the anal canal from repeated scarring that makes it physically harder to pass stool. The third, and most concerning, is an anal fistula, an abnormal tunnel that forms between the inside of the anal canal and the skin outside. Fistulas typically require surgery to fix.
These complications aren’t common, but they illustrate why it’s worth treating a fissure rather than simply waiting it out indefinitely.
How Most Fissures Heal
The first line of treatment is straightforward: eat more fiber, drink plenty of water, and take warm sitz baths (sitting in a few inches of warm water for 10 to 15 minutes) after bowel movements. Sitz baths help by relaxing the internal sphincter muscle, which eases the spasm cycle that keeps the tear from closing. These measures alone resolve the majority of acute fissures.
The recurrence rate matters here. If you go back to a low-fiber diet after healing, fissures come back 30 to 70% of the time. Sticking with a high-fiber diet long term drops that recurrence rate to 15 to 20%. In practical terms, this means the fissure itself isn’t serious, but the dietary habits that caused it need a permanent fix.
Prescription Options for Stubborn Fissures
When home care isn’t enough, your doctor may prescribe a topical ointment that relaxes the sphincter muscle and increases blood flow to the tear. The most commonly prescribed option heals fissures in about 49% of cases compared to 36% with a placebo. It works, but headaches are a very common side effect, with about 1 in 5 people experiencing headaches severe enough to stop using it. Dizziness affects a smaller number of users. Late recurrence is also an issue: roughly half of people whose fissures heal with the ointment see them return.
Other topical options exist, including calcium channel blocker creams, which your doctor may suggest if the first-line ointment causes intolerable side effects.
When Surgery Becomes Necessary
For chronic fissures that don’t respond to medications, a minor surgical procedure called a sphincterotomy is the standard treatment. The surgeon makes a small cut in the internal sphincter muscle to permanently reduce the tension that’s preventing healing. It has a 95% success rate.
Long-term complications from the procedure are rare, occurring in fewer than 5% of cases. The most discussed risk is minor incontinence, meaning small leaks of stool or gas. For most people, this resolves during recovery, though it can persist longer in a small number of cases. The surgery itself is typically outpatient, meaning you go home the same day.
When Bleeding Could Mean Something Else
One reason people search whether anal fissures are serious is that rectal bleeding is unsettling. It’s worth knowing what fissure bleeding looks like compared to something more concerning. Fissure bleeding is bright red and shows up on the surface of your stool or on toilet paper. The pain is sharp and directly tied to bowel movements.
Bleeding from higher in the digestive tract, such as from a colorectal tumor, looks different. The blood is often darker, mixed into the stool rather than sitting on top, or it can make stool appear black and tarry. Pain from colorectal cancer tends to be persistent abdominal cramping or discomfort that doesn’t come and go with bowel movements. Unexplained weight loss, a change in stool caliber that lasts weeks, or bleeding that doesn’t match the typical fissure pattern are all reasons to get evaluated promptly. A fissure in someone over 50 who hasn’t had a recent colonoscopy also warrants a closer look, since the symptoms can overlap.
For the vast majority of people, an anal fissure is a painful but minor condition. Treating it early with fiber and sitz baths prevents it from becoming chronic, and even chronic fissures have highly effective treatment options. The main risk isn’t the fissure itself but ignoring it long enough for complications to develop.