Anal stenosis is a condition that can cause significant discomfort and pain and directly affect the quality of daily life, especially during bowel movements. This condition can be caused by several reasons, including previous surgeries, chronic infections, or congenital defects.
In this article, we review the main causes, diagnostic methods, and the available anal stenosis treatment options, ranging from conservative treatments to surgical interventions to effectively restore normal function and relieve symptoms.
What is anal stenosis?
Anal stenosis is a rare medical condition in which there is a narrowing of the anus, the opening through which stool is passed. The narrowing is caused by shrinkage or fibrosis of the anal muscles that control the passage of feces, which interferes with normal bowel movements. Anal stenosis often occurs in adults as a complication of previous surgeries or chronic diseases, but some children may be born with the condition, known as Congenital Anal Stenosis (CAS). Although it is rare in both adults and children, researchers continue to study its exact prevalence. It is important to start anal stenosis treatment early, as neglecting it can lead to serious health complications.
The difference between congenital and acquired stenosis
Congenital anal stenosis is a narrowing of the anal canal that is present at birth, often due to a congenital malformation or other birth defect. Acquired anal stenosis develops later in life for reasons such as surgical complications, inflammatory conditions, or infection.
- Congenital anal stenosis: This type of stenosis is seen from birth and is often diagnosed during early childhood. An abnormal narrowing of the anus characterizes it and may be associated with abnormalities in the shape or location of the opening. In some cases, the anus is surrounded by healthy sphincters, but is too narrow due to congenital defects that affect the normal configuration of the area.
- Acquired anal stenosis: This type occurs after birth and is the result of multiple factors, most notably the formation of scar tissue after surgeries such as hemorrhoidectomy or chronic infections such as Crohn’s disease. It can also be caused by conditions such as tuberculosis or as a result of radiation therapy. These causes lead to chronic fibrosis or inflammation that gradually narrows the anal canal.
What are the common causes of anal stenosis?
Adult anal stenosis occurs when scar tissue develops inside the anus, causing hard, unstretchable fibers to build up in the walls of the anal canal, narrowing the space. This tissue often appears after medical or surgical treatments in or near the anal area, but it can also be caused by chronic diseases that cause persistent inflammation. Studies show that about 90% of anal stenosis cases are associated with scar tissue formation after hemorrhoid surgery. There are several conditions that can lead to the buildup of scar tissue, including:
- Infectious and environmental causes: Although anal stenosis is not a contagious disease, certain infections, especially sexually transmitted infections or chronic infections such as inflammatory bowel disease, can lead to inflammation and scarring of the anal canal. Environmental factors such as exposure to irritants or allergens can also contribute to the condition.
- Genetic and autoimmune causes: There may be a genetic predisposition in some individuals, especially those with a family history of gastrointestinal diseases. Autoimmune diseases such as Crohn’s disease can also contribute to chronic inflammation leading to anal stenosis.
- Lifestyle and dietary factors: A diet low in fiber can lead to constipation, which increases pressure on the anus and contributes to its narrowing. Lack of physical activity and long-term use of irritant medications can also exacerbate the issue.
- Blood loss or sepsis that leads to damage to anal tissues
- Bacterial or parasitic infections, such as amoebas
- Radiation therapy for anal cancer
- Excessive use of laxatives
Risk factors
- Age: The likelihood of infection increases with age due to gastrointestinal changes.
- Gender: Some studies suggest that males are more susceptible to this condition than females.
- Geographical location: Inflammatory bowel disease rates are higher in some regions.
- Health history: Risk factors include previous gastrointestinal disorders, anal surgery, or chronic constipation.
Symptoms of anal stenosis and when to see a doctor
Symptoms vary from person to person, and their severity depends on the degree of stenosis. However, there are a number of common symptoms that occur in most sufferers that require anal stenosis treatment, including:
- Diarrhea and fecal incontinence: In some cases, a partial blockage may cause liquid stool to accumulate behind the stricture, causing it to leak involuntarily.
- The sensation of not completely emptying: The feeling that the rectum is still full despite having a bowel movement is a common sign of anal canal stenosis.
- Difficulty or pain during bowel movements: As a result of increased pressure on the anal area, the patient may feel an excessive need to exert effort when passing stools.
- Rectal bleeding: Blood may appear on the surface of the stool or on wiping, as a result of hard stools rubbing against inflamed or scarred tissue.
- Change in the shape of the stool: Stools are often thin or ribbon-shaped (pencil-like), reflecting the narrowing of the anal canal.
- Chronic constipation: This is the most prominent symptom and is caused by difficulty passing stool through the narrowed anal canal.
- Pain and discomfort in the anal area: The pain may accompany bowel movements or persist even afterward.
- Itching or irritation: Due to chronic inflammation of the skin around the anus.
Warning signs requiring urgent anal stenosis treatment
- Heavy anal bleeding
- Sharp, persistent pain that doesn’t go away
- Signs of infection such as fever and swelling or redness around the anus
- Complete obstruction with no gas or feces
Symptoms of anal stenosis in infants
The most serious indicator is the absence of meconium (an infant’s first stool) within the first 48 hours of birth, which is often a sign of a lower gastrointestinal issue, such as Hirschsprung’s disease. Additional symptoms in infants suggest infection and the need for anal stenosis treatment:
- Constant crying with difficulty calming him down
- Thin or absent stools for long periods of time
- Signs of dehydration, such as fewer wet diapers (fewer than 6 diapers a day) or a sunken spot on the baby’s head (fontanelle)
How to diagnose anal stenosis
The diagnostic methodology differs between infants and adults due to the different symptoms and clinical conditions associated with each age group.
Diagnosis of Congenital Anal Stenosis in Infants (CAS)
Congenital anal stenosis is usually detected during the first few days of an infant’s life, during a routine newborn clinical examination. This includes digital rectal examination, which is the gentle insertion of a gloved finger into the anus to assess the size and resistance of the anal canal. Early signs of congenital anal stenosis mentioned earlier and to confirm the diagnosis, advanced imaging tests may be required as part of the anal stenosis treatment process, such as:
- Ultrasound to evaluate the internal anatomy of the abdomen and rectum.
- A barium enema, which shows the shape of the intestines and reveals any narrowing or blockage.
- Computerized tomography (CT scan) is used in some complex cases to provide an accurate view of the anatomical structures.
Diagnosis of anal stenosis in adults
In adults, diagnosis begins with gathering a detailed medical history, including current symptoms, history of constipation, previous anal or pelvic surgeries, and any chronic diseases such as inflammatory bowel disease. Steps in the medical evaluation include:
Digital rectal examination: To check the elasticity of the anal canal and detect any narrowing or hardening of the wall.
Anoscopy: Allows the anal canal to be seen using a small lighted tube.
Proctoscopy: A more in-depth examination used to evaluate the rectum and the lower part of the colon.
In some cases, a magnetic resonance imaging (MRI) scan of the pelvis or colonoscopy may be ordered if comorbidities are suspected. These methods are necessary to diagnose and begin anal stenosis treatment.
Anal stenosis treatment without surgery
Non-surgical options, while limited, are often used as the first step in anal stenosis treatment, and include
- Fiber supplements: Help increase stool volume and improve intestinal motility.
- Stool softeners and moisturizing laxatives: Make it easier for stool to pass through the narrow anal canal by softening it and reducing friction.
- A diet rich in fluids: Encourages better bowel movements and reduces constipation, which relieves pressure on the anus.
- If dietary changes or the use of laxatives do not produce effective results, your doctor may recommend manual anal dilation or the use of dilators, which can be performed in a clinic or learned to do at home with specialized tools.
Are topical creams and laxatives enough to anal stenosis treatment?
Although laxatives are often used in anal stenosis treatment to relieve the symptoms of anal stenosis, they are not a comprehensive treatment for the condition, as they work to soften the stool and facilitate its passage, which reduces the stress and discomfort during defecation, but they do not address the root cause of the stenosis. Anal stenosis is a condition characterized by an abnormal narrowing of the anal canal, which may be caused by scarring from surgery or inflammation and spasm of the muscles surrounding the anus, as well as tissue damage due to chronic diseases or recurrent infections.
In mild cases, laxatives may be part of a conservative anal stenosis treatment plan along with diet and lifestyle changes. However, when the stenosis is moderate to severe, treatment often requires additional procedures such as:
- Progressive anal dilation
- Physical therapy for sphincter muscles
- Surgical intervention, such as an anal prosthesis or sphincterotomy
When is manual or balloon dilation used to treat a anal stenosis treatment?
Among non-surgical treatment options, manual or balloon dilation is one of the most effective interventions, especially when not responding to conservative treatments or in the early stages of stenosis.
Manual dilation for anal stenosis treatment
This method is often used for mild to moderate stenosis, whether caused by previous surgery or post-surgical complications.
- Dilation is done gently, using a finger or special medical dilators, to gradually widen the anus.
- It can be performed at home with patient training or under the supervision of a doctor in a clinic.
- It is sometimes used as part of a long-term treatment plan to keep the anus open.
Balloon dilation to treat anal stenosis
This technique is used in cases where the stenosis is more severe or unresponsive to manual treatments.
- A catheter with a balloon is inserted into the anal canal, and the balloon is gradually inflated to expand the affected area.
- This type is usually performed in a medical setting under the supervision of specialists, and is also used when the stricture extends into the upper rectum.
- Balloon dilation is more accurate and may relieve symptoms more effectively in some complex cases.
Surgical treatments available for anal stenosis
The recovery time after anal stenosis treatment and dilation varies from one patient to another depending on the patient’s health condition and the way the procedure is performed, but complete rest must be obtained for at least 24 hours after the procedure, and the patient returns to normal life within three to six weeks, and there are some cases that take months until complete recovery.
Laser surgery or microdiscectomy for anal stenosis
Laser surgery is a modern and effective option for treating a anal stenosis, especially when conventional treatments have failed or are not suitable for the patient’s condition. This technique utilizes precise laser energy to remove strictures and is often employed in conjunction with other procedures, such as sphincterotomy, to enhance results.
How lasers work to treat anal stenosis
- Removing scar tissue with high precision: The laser enables the removal of fibrous tissue that causes narrowing of the anal canal, while minimizing damage to surrounding healthy tissue.
- Relaxing tight muscles: A laser can be used to make a precise incision in the internal sphincter (sphincterotomy), which reduces muscle tension and improves the passage of stool.
- Improving the shape and function of the anal canal: The laser helps rebuild the damaged area of the anal canal, supporting a return to normal function.
Advantages of laser surgery
- Minimally invasive and fewer complications: Thanks to high precision, laser surgery minimizes the risk of infection, bleeding, or tissue damage.
- Less pain and faster recovery: Patients who undergo this type of surgery usually experience less discomfort after the procedure and return to normal life in a relatively short period of time.
- Long-lasting results: Evidence suggests that lasers may have lower recurrence rates than some traditional procedures, especially when used for chronic scarring.
When is laser surgery recommended?
- For mild to moderate stenosis: Suitable for patients who have not responded adequately to conservative treatment, such as laxatives or manual dilation.
- When there are complications that prevent traditional surgery: Lasers are an ideal option for patients who cannot undergo more invasive surgical techniques due to other health issues.
- As part of reconstructive surgery: In severe cases, laser surgery may be used in conjunction with proctoplasty to reconstruct the damaged area and improve function.
Treatment results and recovery after surgery for anal stenosis treatment
In most cases, anal stenosis treatment provides significant symptom relief, with patients noting improved ability to have a bowel movement, reduced pain, and a reduction in associated symptoms such as bleeding or a feeling of incomplete emptying. Anal stenosis treatment also helps restore the elasticity of the anal canal, which has a positive effect on bowel control and reduces the frequency of blockages or irritation.
After anal stenosis treatment, the patient goes through a recovery phase that includes several important aspects to ensure a full recovery and optimal results. Patients usually experience mild pain or discomfort in the early days, and the length of the recovery period depends on the nature of anal stenosis treatment and the body’s response, which may extend from a few weeks to several months. Pain management is an essential part of the recovery phase, and painkillers prescribed by the doctor can be used to relieve discomfort, while a high-fiber diet is recommended along with the use of stool softeners to avoid constipation, which may increase pain or delay wound healing.
The role of physical therapy and assistive exercises in anal stenosis treatment
Anal sphincter exercises, such as Kegel exercises, are an effective way to strengthen the muscles surrounding the anus and improve control over bowel movements, which can help alleviate symptoms.
Kegel exercises focus on tightening the muscles that are normally used to block gas or stop the flow of urine, the same muscles that should be activated during exercise. It is recommended to tighten and lift the muscles as much as possible, then hold the tension for a few seconds before relaxing. Repeat this exercise several times, emphasizing the isolation of the anal muscles and avoid tightening the muscles of the buttocks or thighs. You can also vary the exercise by lengthening the duration of the stretch or performing short, quick contractions.
Besides Kegel exercises, there are other exercises that can be helpful, such as squats that strengthen the pelvic muscles and improve circulation, buttock stretches that help reduce tension in the pelvic floor area, and pelvic floor stretches that aim to relax tight muscles in that area.
Dietary recommendations to minimize pressure during evacuation
Dietary recommendations are an important part of managing anal stenosis, and it is advisable to gradually increase fiber intake to avoid bloating or gas. The daily diet should include ample amounts of fiber-rich foods such as fruits (such as berries, apples, and oranges) and vegetables (such as broccoli, leafy greens, and carrots) as well as whole grains such as oats, quinoa, brown rice, whole wheat breads, cereals, and pasta. Legumes such as beans, lentils, and peas are also excellent sources of fiber.
In addition, it is important to stay hydrated by drinking enough water daily, which will help soften stools and reduce the risk of constipation. If dietary changes are not enough, your doctor may recommend fiber supplements such as Metamucil or BeneFiber to boost your daily fiber intake.
It is also important to avoid or minimize certain foods that may worsen the condition, such as spicy foods that may increase pain and burning sensations, and constipating foods such as dairy products or some types of legumes. It is also advisable to limit alcohol and caffeine consumption, as they can cause dehydration and make bowel movements more difficult. It is best to stay away from processed or low-nutrient foods, as they lack fiber and may cause digestive upset.
Tips for preventing recurrent stenosis
To prevent the recurrence of anal stricture and to fully benefit from anal stenosis treatment, it is important to focus on maintaining soft, regular stools, gently dilating the anus, and addressing the underlying causes that may be contributing to the stricture. This can be achieved by eating a high-fiber diet that includes fruits, vegetables, and whole grains, as well as drinking enough fluids to keep stools moist. Using stool softeners or laxatives under medical supervision can help prevent constipation and straining during bowel movements.
It is also advisable to avoid excessive pressure during the evacuation process, as straining may increase the chances of re-stenosis. Warm sitz baths help relax the anal muscles and relieve discomfort, which supports the healing process and reduces muscle tension. In some cases, the doctor may recommend regular dilation of the anus using a finger or specialized dilators. In these cases, it is essential to follow the recommended technique precisely with proper lubrication to avoid irritation or trauma.
Treating the underlying causes is an essential part of long-term prevention. If infection or inflammation, such as Crohn’s disease, is causing the stricture, it should be treated with appropriate medications such as antibiotics or anti-inflammatories. If the stricture is the result of previous surgery, it is advisable to contact your doctor to discuss options for prevention and post-operative follow-up.
In conclusion, anal stenosis treatment is a necessary step to improve the quality of life and vital functions associated with defecation. Anal stenosis treatment options vary depending on the severity of the stenosis, ranging from gradual dilation to surgical intervention in chronic cases. Early diagnosis and ongoing medical follow-up are key to achieving effective and sustainable results in anal stenosis treatment.
Sources:
- Hudson, J. I., Hiripi, E., Pope, H. G., Jr., & Kessler, R. C. (2007). The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication. Biological Psychiatry, 61(3), 348-358
- Tsikitis, V. L., & Marecik, S. (2021). Anal fissure and anal stenosis. In S. R. Steele, T. L. Hull, N. Hyman, J. A. Maykel, T. E. Read, & C. B. Whitlow (Eds.), The ASCRS Textbook of Colon and Rectal Surgery (4th ed., pp. 231-248). Springer International Publishing
