Anal fissures are one of the most common anorectal conditions, affecting people of all ages from infants to older adults. They occur roughly as often as hemorrhoids in clinical practice, yet up to 35% of the time, fissure symptoms are mistakenly blamed on hemorrhoids by both patients and doctors. That misattribution means the true number of people dealing with fissures is likely higher than medical records suggest.
Who Gets Anal Fissures
Anal fissures affect men and women at similar overall rates. A large epidemiological study by Mapel and colleagues found no statistically significant difference in fissure incidence between sexes when looking at the population as a whole. The pattern shifts, though, when you break it down by age. Women between 12 and 24 develop fissures at significantly higher rates than men in the same age range, likely due to factors like constipation during puberty and pregnancy. Men between 55 and 64 have notably higher rates than women of the same age.
Most fissures occur in young and middle-aged adults, but they’re far from rare in children. A study of over 400 infants under four months old found fissure prevalence ranging from 6% to 11%, regardless of whether the babies were breastfed, formula-fed, or both. Infants with abdominal discomfort had fissures at three times the rate of those without (19% versus 6%), suggesting that straining and digestive trouble drive the problem even at that age.
Why They’re So Common
The anal canal’s lining is thin and under constant mechanical stress, which makes small tears almost inevitable at some point in life. Constipation is the single biggest risk factor. In a prospective study of pregnant and postpartum women, over 60% reported constipation at some point during the study period, and constipation was identified as a significant independent risk factor for developing anal complaints including fissures.
A history of previous anal problems also raises your risk substantially. If you’ve had a fissure before, the scar tissue left behind is less flexible than healthy tissue, making the same spot vulnerable to re-tearing. Other common triggers include passing large or hard stools, chronic diarrhea (which irritates the lining), and vaginal childbirth. People with inflammatory bowel disease face additional risk. Among patients with ulcerative colitis, the cumulative incidence of anal fissures reached about 5% over 10 years, on top of baseline population risk.
Acute Versus Chronic Fissures
Most anal fissures are acute, meaning they heal on their own or with simple home care within about six weeks. These are the ones you might get from a single episode of constipation or a bout of diarrhea. They tend to look like a fresh, shallow cut and cause sharp pain during bowel movements that fades within minutes to hours afterward.
When a fissure persists beyond six to eight weeks, it’s classified as chronic. Chronic fissures develop deeper, often exposing the muscle layer underneath, and typically have visible signs like a small skin tag at the edge or thickened tissue around the tear. The transition from acute to chronic happens because the internal sphincter muscle goes into spasm in response to the pain, which reduces blood flow to the area and prevents healing. That creates a cycle: the fissure causes spasm, the spasm prevents healing, and the unhealed fissure causes more spasm.
How Often They Come Back
Recurrence is one of the most frustrating aspects of anal fissures, and the rates are higher than most people expect. Even after successful treatment, a significant percentage of fissures return. In a long-term follow-up study, patients treated with botulinum toxin injections (which relax the sphincter muscle to promote healing) had a recurrence rate of about 42% over four years. Patients treated with a topical muscle-relaxing ointment fared even worse, with recurrence reaching 63% within roughly two and a half years.
Surgery offers the most durable results. Lateral internal sphincterotomy, the standard surgical procedure for chronic fissures, has a 95% success rate in curing them. Long-term complications occur in fewer than 5% of cases. This is why surgery is typically reserved for fissures that keep coming back or refuse to heal with other approaches: it’s the option most likely to break the cycle for good.
Healing Timelines
If you’re dealing with a first-time fissure, the odds are in your favor. Most acute fissures heal within a few days to a few weeks with basic measures: increasing fiber intake, drinking more water, and soaking in warm baths. The goal is simply to keep stools soft so the tear isn’t re-injured with each bowel movement.
Chronic fissures take considerably longer. Even with active treatment (prescription ointments or injections), expect six to 12 additional weeks before healing is complete. If surgery becomes necessary, it’s typically an outpatient procedure, meaning you go home the same day. The recovery involves managing soreness for a period while the surgical site heals, but the underlying fissure itself is addressed during the procedure.
Why Fissures Are Often Misdiagnosed
Part of the reason anal fissures seem less common than they are is that they’re frequently confused with hemorrhoids. Both cause pain, bleeding, and discomfort around the anus. Up to 35% of anal fissure cases are initially misattributed to hemorrhoids by patients self-diagnosing at home or by primary care doctors who don’t perform a visual examination. The key difference is the type of pain: fissures cause a sharp, cutting sensation during a bowel movement, often described as passing broken glass, while hemorrhoids tend to produce a duller ache or pressure. Bright red blood on the toilet paper is common to both, which adds to the confusion.
If you’ve been treating what you think are hemorrhoids for several weeks without improvement, especially if your main symptom is sharp pain rather than itching or swelling, the problem may actually be a fissure. The treatments overlap somewhat (fiber, hydration, warm baths), but chronic fissures need targeted therapy that hemorrhoid creams won’t provide.