An anal fissure looks like a small, narrow tear or crack in the skin lining the anal canal, similar to a paper cut. Most are only a few millimeters long and sit along the midline of the anus, usually toward the back (closest to the tailbone). Despite their small size, fissures can cause significant pain and visible bleeding, which is often what prompts people to look more closely or search for answers.
Where Fissures Appear
About 85 to 90 percent of anal fissures occur in the posterior midline, the back wall of the anal canal. Another 10 to 15 percent appear in the anterior midline, toward the front. This predictable location is one of the key ways doctors identify them during an exam.
A fissure that appears off to the side, or multiple fissures at once, is considered atypical. These patterns can signal an underlying condition like Crohn’s disease, infections, or other inflammatory disorders, and they typically warrant further investigation beyond a standard visual exam.
How a New Fissure Looks
A fresh (acute) anal fissure has sharply defined edges with clean, well-demarcated borders, almost like a cut made with a blade. The tissue at the base may appear pink or reddish with granulation tissue, which is the body’s early wound-healing response. The surrounding skin usually looks normal, without raised edges or thickening. Most acute fissures are superficial, meaning they only involve the top layer of the anal lining.
The most common visible sign you’ll notice isn’t the tear itself but the blood. Fissures produce bright red blood, typically a small amount on the toilet paper after wiping or streaked on the surface of the stool. This bright color indicates the bleeding source is close to the surface, near the opening of the anus, rather than higher up in the digestive tract.
How a Chronic Fissure Looks Different
When a fissure doesn’t heal within six to eight weeks, it’s considered chronic, and its appearance changes in several distinct ways. The edges of the tear become thickened and raised (described clinically as “indurated”), losing the sharp, clean-cut look of a fresh wound. The base of the fissure dries out, and the pink granulation tissue that signals healing disappears. In deeper chronic fissures, you may be able to see the horizontal fibers of the internal sphincter muscle at the base of the wound, a whitish band of tissue that becomes exposed as the tear deepens.
Chronic fissures also develop characteristic secondary features. The most recognizable is a sentinel skin tag, a small flap of skin that forms at the outer edge of the fissure, near the anal opening. This tag can look like a small, soft bump and is sometimes mistaken for a hemorrhoid. At the inner end of the fissure, a small raised mound of tissue called a hypertrophied anal papilla may also develop. Together, these two features essentially “bookend” the chronic tear and are reliable visual markers that the fissure has been present for a while.
Fissure vs. Hemorrhoid
People often confuse fissures and hemorrhoids because both cause pain and bleeding in the same area, but they look quite different. A hemorrhoid is a swollen blood vessel that appears as a rounded, soft, purplish or bluish lump near the anal opening. A fissure is a linear tear in the skin, not a lump. If you see a flat crack or split in the tissue rather than a bulging mass, that’s more consistent with a fissure.
The sentinel skin tag that develops with chronic fissures can blur this distinction, since it resembles a small external hemorrhoid. One helpful clue: a sentinel tag sits right at the edge of a visible tear, while a hemorrhoid stands alone as a swollen cushion of tissue without a crack running through it.
What the Bleeding Looks Like
Fissure-related bleeding is almost always bright red and relatively small in volume. You’ll typically see it on the toilet paper, on the surface of the stool, or as a few drops in the toilet bowl. The blood doesn’t mix into the stool the way bleeding from higher in the digestive tract does. Dark, tarry, or maroon-colored blood suggests a different source entirely and needs prompt medical evaluation.
Pain is the other hallmark that distinguishes fissure bleeding from hemorrhoid bleeding. Fissures cause a sharp, cutting pain during a bowel movement that can linger for minutes to hours afterward. Hemorrhoids, by contrast, more often cause painless bleeding or a dull ache.
What You Can See at Home
Most anal fissures are difficult to see on your own because they sit just inside the anal canal rather than on the outer skin. Using a mirror, you might spot the lower end of a fissure near the anal opening, especially if a sentinel skin tag has formed. A fresh, shallow fissure higher up in the canal is unlikely to be visible without a clinical exam. What you’re more likely to notice are the indirect signs: bright red blood on tissue, pain with bowel movements, and possibly a small skin tag near the anus.
If a fissure is deep enough to expose the whitish muscle fibers at its base, or if it appears off the midline, those are signs that the situation may be more complex than a simple tear from constipation. Similarly, multiple tears, extensive skin changes, or drainage beyond blood can indicate something beyond a straightforward fissure.