FAST & FREE 📦 2-DAY SHIPPING!*
Constipation is commonly believed to be the sole cause, but what causes anal fissures can also include diarrhea, childbirth, prior surgery, and a pain-spasm cycle that keeps a small tear from healing.
If you're dealing with sharp pain, burning, or streaks of blood after a bowel movement, it's easy to panic. The good news is that an anal fissure is common, understandable, and often linked to very specific triggers that you can address step by step.
An anal fissure is a small tear in the delicate lining of the anal canal. The simplest way to think about it is a paper cut in a very sensitive place. Because the area stretches during bowel movements, even a tiny tear can hurt a lot.
Many people confuse a fissure with a hemorrhoid. They can happen together, but they aren't the same thing.
A fissure is a tear.
A hemorrhoid is a swollen vein.
That difference matters because the pain pattern is often different. Fissures usually cause sharp pain during or after a bowel movement. Hemorrhoids are more often linked to pressure, swelling, itching, or painless bleeding, though they can also become painful.
Plain-English takeaway: A fissure usually hurts because the skin has torn. A hemorrhoid usually bothers you because tissue has swollen.
The most common cause is mechanical trauma to the anal lining, especially from passing hard or bulky stool during constipation. Major clinical references also identify persistent diarrhea, anoreceptive intercourse, prior anorectal surgery, and obstetric trauma or childbirth as important causes, as noted in the NCBI review on anal fissures.
That list surprises people. They expect the answer to be only constipation. But a fissure can also happen when the area gets irritated again and again, or when the tissue is stretched or injured in another way.
A fissure can begin as a one-time tear, then turn into a longer problem if it keeps getting reopened. Chronic fissures are commonly defined by symptoms lasting more than 6 weeks, which points to ongoing irritation and muscle spasm rather than one brief injury.
If you've been wondering why such a small tear can feel so intense, the reason is what happens next inside the muscle around it.
A fissure doesn't always stay a simple cut. Sometimes it gets trapped in a loop that makes healing harder.
The first step is the tear itself. That may happen after a hard bowel movement, a bout of diarrhea, or another source of irritation. The tissue in that area is sensitive, so the injury can trigger immediate pain.
Then the body reacts by tightening the internal anal sphincter. This tightening is involuntary. You're not doing it on purpose.
That muscle spasm raises pressure in the anal canal. At the same time, the injured area gets less blood flow. The trauma initiates a localized ischemic response in the distal anal canal, and the posterior midline has the lowest blood perfusion density. This creates a vicious cycle of pain-induced sphincter spasm, higher pressure, compression of small blood vessels, and delayed healing.
In plain language, the area needs blood flow to repair itself. But the spasm makes that harder.
The tear hurts. The muscle tightens. Blood flow drops. Healing slows. The next bowel movement reopens the wound.
This is the part many people miss when they ask what causes anal fissures. The original trigger matters, but the repeat injury is what keeps the problem alive.
A person may think, "The stool was softer today, so why does it still hurt?" The answer is that the tissue may still be fragile. Once the cycle is underway, even a normal bowel movement can irritate the partially healed tear.
Here is the cycle in simple steps:
A chronic fissure isn't just an old cut. It's often a fissure stuck in this loop of pain, spasm, and poor healing. That's why treatment usually focuses on more than surface relief. The aim is to reduce trauma, relax the area, and give the tissue a chance to recover.
Constipation is common, but it is only one piece of the picture. An anal fissure usually starts when the lining is stretched or irritated more than it can tolerate, much like skin that cracks after too much pulling and rubbing.
That first injury can happen in everyday ways people do not always connect to fissures.
A lot of readers expect fissures to come only from stool that is hard. Loose stool can cause problems too. If the area is being irritated many times a day, the tissue may not get a chance to settle down. For some people, diarrhea starts the problem just as clearly as constipation does.
Constipation is really a problem of stool consistency and effort, not just frequency. Stool that sits longer in the bowel tends to lose water. Then passing it takes more force.
A simple way to picture it is this. Soft stool moves through like clay. Hard stool behaves more like a dry, rough lump. The more force it takes to push out, the more likely the delicate lining is to split.
This is why a person can say, "I still go every day," and still have constipation-related strain. Daily bowel movements do not rule out hard stool, pushing, or incomplete emptying.
Practical rule: If bowel movements are hard, painful, or require straining, the anal lining is under repeated stress.
Some fissures begin after childbirth, especially after stretching and tissue strain during vaginal delivery. Others appear after anorectal surgery or anoreceptive intercourse, when the lining has been irritated or mechanically stretched.
These causes matter because they explain a common and confusing experience. Someone develops a fissure even though their stool is soft and their bowel habits seem normal. In that case, the trigger may have been local trauma, repeated irritation, or a period of heavy strain on the tissue rather than classic constipation.
Bathroom habits can also add up over time. Long sessions on the toilet, repeated wiping, and pushing "just in case" can all increase irritation. None of these guarantees a fissure, but together they can make a sensitive area easier to injure.
The big takeaway is reassuring. If you were not constipated, that does not mean your symptoms make no sense. Fissures have more than one starting point, and knowing the likely trigger helps guide prevention and healing.
Anal fissures do not happen only to people with classic constipation. They also show up during life stages and health conditions that put extra stress on a very small, delicate area.
After delivery, it is easy to assume rectal pain must be hemorrhoids. A fissure can cause the same kind of alarm, and some people have both at once.
Childbirth can stretch and strain the anal tissue during vaginal delivery. Then the first bowel movements after birth may feel intimidating, delayed, or painful. That matters because fear of pain often leads to holding stool in, and held stool tends to get drier and harder. The next trip to the bathroom can then reopen the tear.
This is one reason postpartum fissures can become so frustrating. The original injury may happen during delivery, but the pain-spasm cycle can keep the area from settling down.
Fissures are also seen more often at the two ends of the age range. In infants, a change in feeding or bowel pattern can lead to straining and a small tear. Parents may notice crying with bowel movements or a streak of bright red blood on the diaper.
In middle-aged and older adults, the pattern is often less obvious. Hard stool is one part of the story, but it is not the whole story. Medications, lower activity, irregular bathroom habits, repeated wiping, and bouts of diarrhea can all irritate the lining over time. A fissure can start from one rough bowel movement, then linger because the anal muscle tightens around the sore spot like a clenched fist protecting a paper cut.
That muscle tightening is easy to miss. People often focus on the bowel movement that started the problem, but the ongoing spasm is often what keeps it going.
Sometimes a fissure is a straightforward injury. Sometimes it is a clue.
A fissure that keeps coming back, sits off to the side instead of the usual location, or looks unusually inflamed may be linked to an underlying condition such as Crohn's disease or an infection. In those cases, the tear is not just a local wound. It may be part of a bigger medical problem affecting how the tissue heals.
If your symptoms seem unusual, severe, or hard to explain, it is wise to get checked rather than assume it is a simple fissure.
This can feel worrying, but it is also useful information. When the underlying driver is identified, treatment can focus on both the tear and the reason it is not healing.
Preventing a fissure is only part of the job. Healing depends on stopping the pattern that keeps re-opening the same small tear.
A fissure often behaves like a paper cut in a place that keeps getting stretched and rubbed. One hard stool can start it, but so can diarrhea, frequent wiping, or the strain that follows childbirth. Then pain makes the anal muscle tighten. That tightening reduces blood flow, bowel movements hurt more, and healing slows. Breaking that cycle is the goal.
Guidance from sources such as the Mayo Clinic overview of anal fissure causes and care points to the same practical idea: keep bowel movements easier to pass, reduce irritation, and help the muscle relax.
Warm sitz baths can relax the muscle and make bathroom trips less frightening. That matters because fear often leads people to hold stool in, which sets up the next painful bowel movement.
Some people also use topical products for symptom relief. For over-the-counter options, Revivol-XR is one example of a product line used for fissure and hemorrhoid symptom support, including creams and sitz bath products.
This short video can help you think through practical care steps at home.
Protect the area while it heals.
That means less straining, less friction, less panic, and fewer bowel habits that swing between constipation and diarrhea. Small daily choices can calm the spasm and give the tissue a fair chance to close fully, instead of tearing open again with the next bowel movement.
Most fissures improve with good self-care, but some need medical treatment. You don't have to wait until the pain is unbearable.
See a doctor if any of these apply:
Medical care often starts with a physical exam and a symptom review. A clinician may recommend topical treatments to reduce pain and help the area relax. Some products use lidocaine for numbing relief.
If a fissure has become chronic, treatment may also include office-based procedures or surgery aimed at reducing sphincter spasm and helping the area heal. That can sound intimidating, but the main point is reassuring. Persistent fissures are treatable.
Relief is possible. A fissure that hasn't healed on its own doesn't mean you're stuck with it.
If you need practical symptom support while you're working on softer bowel movements and gentle healing, Revivol-XR offers over-the-counter options for fissure and hemorrhoid care, including topical relief and sitz bath support.
5 SEO-driven title options
Slug
what-causes-anal-fissures
Focus Keyphrase
what causes anal fissures
SEO Title
What Causes Anal Fissures? Common Triggers and How to Heal
Meta Description
What causes anal fissures? Learn the main triggers, why they don't heal, and simple steps to reduce pain and prevent repeat tearing.
Categories
Prevention, Relief Tips
Tags
anal fissure, constipation, diarrhea, postpartum relief, sitz bath, pain relief, hemorrhoid care, Revivol-XR
Author in WordPress
Hemorrhoid.com
Featured Image
Filename: what-causes-anal-fissures-featured.jpg
Alt text: Understanding what causes anal fissures and how to prevent repeat tearing
Status
Draft ready
Time log
Worked for 26 minutes.
Word Count
Approx. 1,650
Yoast
Readability = likely Green
SEO = likely Green
Notes
Outbound links included. No internal article link requirement was provided in the plan. All required section images were included once, and the required video placement was separated from the image by substantive text. No em dashes used. Publish?
