An anal fissure is characterized by a tear in the anus’s thin, wet tissue lining. Since the mucous lining is more delicate and thinner than normal skin, it is more prone to tearing when one has difficult bowel movements. Bleeding, pain, and occasional muscle spasms in the anal sphincter occur with bowel movements. Although it can affect people of all ages, it is most common among young infants, and babies can have frequent anal fissures.

Causes
Some of the common causes of an anal fissure include:

Constipation
A constipated stomach leads to straining during bowel movements.
Passing hard or large feces during a bowel movement
This puts pressure on the anus and surrounding areas
Chronic diarrhea
Constant bowel movements lead to tension in the anus muscles.
Anal intercourse
Stress on the anus muscles during anal penetration can result in tears
Childbirth
Excessive pressure during childbirth can also lead to anal fissures in mothers.
Crohn’s disease
This inflammatory bowel ailment can cause inflammation in the intestinal tract, making it more prone to tearing.
Age
While they can afflict people of any age, fissures are most often noticed in middle-aged adults and infants.
Other causes, such as trauma, can cause the anal lining to tear for various reasons,, and some pre-existing health conditions can also lead to tears and fissures. Conditions like anal cancer, tuberculosis, HIV, obstructed defecation syndrome, syphilis, prior surgery, infant dyschezia, diaper rashes, and sexually-transmitted infections (STIs) can also cause fissures.

Symptoms
The symptoms of an anal fissure include:

Pain lasting up to several hours, following bowel movements
Noticing blood stains on the toilet paper or stool following a bowel movement
A noticeable skin crack encircling the anus
A skin tag or a small lump is seen on the skin near the anal fissure
Sharp pain felt while defecating
Feeling a burning or itching sensation when passing stool
Muscle spasms in the anal muscles
Pain occurring at intervals

One thing to note is that the symptoms of anal fissures might seem similar to those of hemorrhoids. So, it is important to note the difference so that it is diagnosed and subsequently treated properly.

Treatment
Most anal fissures heal quickly with home remedies like increased fiber intake and a warm water bath and soak. However, if these approaches do not have the desired effect and your symptoms persist, your healthcare provider might suggest some stronger treatments for you. These include:

Non-surgical treatments
External application substances to help increase blood flow, relieve pain, and promote healing of the fissure
Therapies to relax sphincter muscle spasms and paralyze the anal sphincter
Blood pressure treatments are applied onto the skin but can also be orally taken.

Surgical treatment
In case of a chronic anal fissure resistant to non-invasive and non-surgical approaches, or with severe symptoms, doctors might recommend undergoing a surgical procedure. This operation is usually the LIS or the lateral internal sphincterotomy. In this process, a small portion of the anal sphincter muscle is cut. It is known to have a better effect than any other form of treatment. However, it is important to be aware that a major side effect of this procedure is incontinence.