Anal Stenosis
Anal stenosis, also known as anal stricture, is a rare, debilitating condition that occurs as a result of a narrowing at the bottom of the anal canal. The disorder results in difficulty passing stool. Anal stenosis is sometimes found in infants due to a congenital disorder. In adults, it may result from a number of causes, usually involving scarring. Scar tissue, because it is considerably less pliable than normal tissue, tends to create a blockage, causing a narrowing of the anal canal. At times, because the condition develops gradually, patients believe they are simply constipated. Unfortunately, continually straining during bowel movements can result in further injury to the area, resulting in more scarring and increased muscle strain and nerve irritation, all of which may exacerbate the problem.
Causes of Anal Stenosis
Anal stenosis may be the result of an inherited congenital abnormality, in which the infant's rectum or anus may be misshapen or inappropriately located. Other causes of the disorder may be:
- Postsurgical scarring, especially after a hemorrhoidectomy
- Perianal fissure
- Perianal fistula
- Traumatic injury to the area
- Inflammatory bowel disease
- Sexually transmitted disease
- Excessive use of laxatives
In most cases of anal stenosis, the underlying cause is scarring in the perianal region. Such scarring may occur because of anal sexual activity, a traumatic injury, or as a result of surgery or disease. Any of these reasons for scarring may also result in strained rectal and anal muscles, spasms of the anal sphincter, and irritation of the region's nerves, particularly the pudendal nerve. Unfortunately, the cramping that results further constricts the rectum and anus.
Symptoms of Anal Stenosis
There are several symptoms of anal stenosis which include:.
- Difficult or painful bowel movements
- Rectal bleeding
- Unusually narrow, ribbon-like feces
- Inability to evacuate fully
Many patients with anal stenosis experience ongoing anal discomfort or pain.
Diagnosis of Anal Stenosis
In order to definitively diagnose anal stenosis, and to gauge the extent of the disorder, both a digital and anoscopic examination of the anal canal is necessary. Because of the folds of the mucosa in the region, it is important that the entire circumference of the anal canal be thoroughly palpated.
Treatment for Anal Stenosis
Mild cases of anal stenosis can be treated with nonsurgical methods, such as fiber supplements or stool softeners. For more severe cases, an anoplasty is usually necessary. An anoplasty is a surgical procedure performed to reconstruct the anus and widen the anal canal.
Performed under general anesthesia, anoplasty involves stretching the anal canal so that stools can be passed comfortably. Most patients will be able to undergo the procedure on an outpatient basis. The stitches in the anal canal will dissolve on their own, with the wound is generally completely healed in several weeks. Some patients may experience a small amount of bleeding in the days after the anoplasty, but any complications following the surgery are typically mild.