Anus – structure, functions, the most common diseases and ailments. Hygiene of the anus

Proven content

The anus (from Latin anus) is an opening located inside the buttock fissure and separated from the genitals by the perineum. Two sphincters control the excretion of faeces from the body during defecation, which is the primary function of the anus. These are the internal anal sphincter and the external anal sphincter, which are the circular muscles that normally keep the mouth constricted and that relax as required for normal physiological functioning. Due in part to its contact with feces, the anus can be affected by a number of health conditions such as hemorrhoids. The anus is also exposed to potential infections and other medical conditions, such as cancer. The anus also plays an important role in anal sex.

Anus – construction

The anus is the last part of the digestive tract and it exits directly from the rectum. The anus passes through the pelvic floor and is surrounded by muscles. The upper and lower parts of the anus are flanked internal and external anal sphincters, two muscle rings that control bowel movements.

The rectum is surrounded along its entire length by folds called anal valves that converge in a line known as the crest line. This is the point of transition between the posterior gut and the ectoderm. Below this point, the mucosa of the internal anus becomes the skin. The crest line is also the division between the internal and external anus.

The rectum receives blood from the lower rectal artery and innervation from the lower rectal nerves that branch from the labia nerve.

Anus – functions

The anus is the final section of the human digestive tract. Thanks to its structure, it allows you to maintain and pass stool at will, as well as stop the passing of gases.

Intrarectal pressure increases as the rectum fills up with feces, pushing the feces against the walls of the anal canal. Contractions of the abdominal muscles and pelvic floor can create pressure in the abdomen, which further increases intra-rectal pressure. The internal anal sphincter responds to the pressure by relaxing, thus allowing the feces to enter the canal. The rectum shortens as the feces are pushed into the anal canal and the peristaltic waves push the feces out of the rectum. The relaxation of the internal and external anal sphincters allows the feces to exit the anus, eventually as the levator ani muscles pull the anus up over the outgoing feces.

See also: Digestive system – functions. Elements of the digestive system and their role

Anus – diseases

Various medical conditions and diseases can affect the rectum or have symptoms visible within it. The most common are, among others, hemorrhoids or anal fissure.

Anal diseases – internal hemorrhoids

Internal hemorrhoids are normal blood vessels that line the inside of the anal opening. We were born with them. It is believed that they allow us to hold on to gases and avoid them spreading until it becomes “socially acceptable”. When internal hemorrhoids enlarge as a result of exercise or pregnancy, they can become irritated and start bleeding. Occasionally, internal hemorrhoids can become large enough to bulge beyond the anal opening.

Traditional treatment of internal hemorrhoids includes improving bowel habits, using elastic bands to pull the hemorrhoids back into the rectum, or surgically removing them. Devices that use sound waves can accurately detect where there is excessive blood flow in these vessels and allow the clinician to identify the area specifically. Another procedure is hemorrhoidectomy, in which a special device is used to pull the hemorrhoidal tissue back into the body and stitch it into place.

See also: What do hemorrhoids look like and how to treat them?

Anal diseases – external hemorrhoids

External hemorrhoids are veins that lie just under the skin on the outside of the anus. They usually don’t cause any symptoms. Occasionally a blood clot can form which can be very painful. These are not dangerous blood clots that can spread to other organs. The biggest problem they raise is pain. These types of problems may disappear on their own over time. Sometimes, however, the clot must be removed under local anesthesia in a doctor’s office.

Anal diseases – anal fissure

An anal fissure is a tear in the anal lining that occurs after an injury. It can happen as a result of hard stools or even diarrhea. Rarely, it can also be caused by penetration into the anus during anal sex. The fissures contract the anal sphincter (the muscle ring that keeps the anus closed), which worsens pain and prevents healing. Anal fissures can occur in people of all ages, but are most common in infants.

An anal fissure causes pain and bleeding, usually during or shortly after you have a bowel movement. The pain lasts from a few minutes to several hours and then subsides until the next bowel movement.

Treatment includes the use of a stool softener or psyllium, or increasing dietary fiber intake, which can reduce the risk of injury from hard or heavy bowel movements. Healing is sometimes aided by the use of zinc oxide ointments or glycerin suppositories that lubricate the lower part of the rectum and soften the stool.

Applying a local anesthetic (such as benzocaine or lidocaine) to the anus or soaking in a warm (non-hot) bath for 10 to 15 minutes after each bowel movement relieves discomfort and helps increase blood flow, which promotes healing. Soaking is done by squatting or sitting in a partially filled tub, or by using a container filled with warm water placed on the toilet bowl.

To reduce contraction of the anal sphincter and speed up healing of fissures, doctors may inject botulinum toxin into the anal sphincter or have the patient apply nitroglycerin ointment or calcium channel blockers (such as nifedipine cream or diltiazem gel) over the fissure area.

If these measures don’t work, you may need surgery. To relieve sphincter contractions, doctors cut out part of the internal sphincter (called a sphincterotomy).

See also: How to deal with problems with bowel movements?

Anal Diseases – Anal itching

Most often, doctors do not identify a specific disorder as the cause of anal itching, and the itching goes away without treatment after a while. Many other cases of anal itching are due to hygiene concerns. Only a few cases are caused by a specific disorder, such as pinworms or a fungal infection. Of the specific causes, only rare causes such as inflammatory bowel disease and perianal skin cancer are considered serious.

Not every episode of anal itching requires immediate medical evaluation. Certain symptoms and characteristics, however, are cause for concern. These include: discharge of pus from or around the anus; bloody diarrhea; raised or protruding hemorrhoids; rectal skin soiled with fecal material; gray or thickened skin around the anus.

People who suffer from itchy anus and bloody diarrhea or oozing pus should see their doctor in a day or two. Other people should see their doctor if the itching persists for more than a few days but the visit is not urgent.

The doctor will perform a physical examination. What he finds during an interview and physical examination often suggests the cause of the itch. If your doctor doesn’t see any abnormalities on or around your anus, he or she doesn’t usually do any examinations and just treat the symptoms. If there are any visible skin abnormalities, your doctor may remove a small piece of tissue for examination under a microscope (skin biopsy).

The best way to treat anal itching is to treat the underlying condition. For example, medications can be taken for parasitic infections (such as pinworms), and creams can be applied to fungal infections (such as Candida, also called yeasts). Irritating foods can be eliminated from the diet or avoided temporarily to see if the itching reduces. If possible, antibiotics can be stopped or changed.

See also: Pinworms in children – symptoms, treatment

Anal diseases – perianal abscess

There are tiny glands around the anus on the inside of the anus that open up and possibly help you pass stools. When one of these glands becomes blocked an infection may develop and an abscess (purulent pocket) may appear.

An abscess can cause significant damage to nearby tissue and can rarely lead to a loss of bowel control (faecal incontinence). People with Crohn’s disease are particularly vulnerable to perianal abscesses. Sometimes abscesses are a complication of diverticulitis or pelvic inflammatory disease.

Your doctor can usually see an abscess if it is in the skin around the anus. However, when no external swelling or redness is visible, your doctor can diagnose an anal abscess by examining the rectum with a gloved finger. A tender swelling in the rectum indicates an abscess. If your doctor suspects a deep abscess or Crohn’s disease, a computerized tomography (CT) scan can determine the extent and location of the lesion.

In the case of an abscess just below the skin, treatment consists of incising the abscess and draining the pus after administration of local anesthesia. In the case of a deeper abscess, the person is usually hospitalized and the abscess is drained in the operating room after general anesthesia.

Even with proper treatment, a drained abscess can lead to the formation of an abnormal canal from the anus or rectum to the skin (so-called anal fistula).

Antibiotics are usually only given to people who have a fever, a weak immune system, diabetes, cellulitis, or an infection elsewhere in the body. People with an abnormally low white blood cell count (neutropenia) receive antibiotics, but the abscess is usually not drained.

See also: Symptoms of reduced immunity – this is how the body warns you

Anal diseases – perianal fistula

In approximately 50% of cases, once an anal abscess is drained, a tunnel develops from the gland on the inside of the anus to the skin around the anus. This is called a perianal fistula.

Fistulas are more common in people with Crohn’s disease or tuberculosis. They also occur in people with diverticulitis, cancer, or an anus or rectal trauma. An infant fistula is usually a birth defect and is more common in boys than in girls. Fistulas that connect the rectum and the vagina (called rectovaginal fistulas) may be the result of radiation therapy, cancer, Crohn’s disease, or an injury to the mother during childbirth.

The doctor usually sees one or more fistula openings, or may feel a fistula beneath its surface. You can enter a probe to determine its depth and direction. By looking through the anoscope inserted into the rectum and examining the probe, the doctor can locate the internal opening of the fistula. Endoscopy also helps the doctor locate the inner opening of the fistula and determine if the problem is caused by cancer, Crohn’s disease, or another condition.

So far, the only effective treatment has been the operation to open a fistula (fistulotomy). During the operation, the sphincter is sometimes partially cut. If too much of the sphincter is cut, it may be difficult for the person to control bowel movements. Newer surgical procedures use flap shifting (the flaps are stretched over the mouth of the fistula) or other procedures to close the fistula canal. An alternative to fistulotomy are biological plugs and instillation of fibrin glue.

See also: Childbirth is beautiful, but not necessarily easy

Diseases of the anus – cancer of the anus

Anal cancer develops in the skin cells of the closest area around the anus or in the lining of the transition zone between the anus and the rectum (anal canal). Unlike the rectum and colon, where tumors are almost always adenocarcinomas, rectal cancers are primarily squamous cell carcinomas.

It is assumed that anal cancer constitutes 1-3% of all malignant neoplasms located in the large intestine. The peak incidence of anal cancer occurs after the age of 60. Anal cancer is more common in women.

Risk factors include: human papillomavirus (HPV) infection; anal intercourse; chronic fistulas; radiotherapy on the skin of the anus; leukoplakie; venereal lymphoma infection; human immunodeficiency virus (HIV) infection; smoking.

People with anal cancer often experience bleeding with bowel movements, pain, and sometimes itching around the anus. About 25% of people with anal cancer have no symptoms. In this case, the tumor is detected only during a routine examination.

To diagnose anal cancer, the doctor first checks the skin around the anus for any abnormalities. Using a gloved hand, the doctor examines the anus and the lower part of the rectum for any parts of the lining that feel different from the surrounding tissue to the touch. A flexible sigmoidoscope (short tube with a camera at the end) is used to evaluate the anus and rectum. An anoscope (a small, rigid tube equipped with a light) may be inserted several inches into the anus to aid in the examination.

The doctor then takes a tissue sample from the abnormal area and examines it under a microscope (called a biopsy). If the patient has bleeding, doctors may perform a colonoscopy to look for coexisting colorectal cancer. The entire colon is examined during a colonoscopy. Colonoscopy can be performed even on people with visible hemorrhoids that may cause bleeding.

In the treatment of anal cancer, the first choice is radiotherapy combined with chemotherapy. Surgery is performed on people whose cancer does not go away with radiation and chemotherapy, or goes away and comes back. During the operation, the doctor must be careful not to interfere with the functioning of the muscle ring that keeps the anus closed (anal sphincter). The anal sphincter remains closed until the person has a bowel movement. A malfunctioning sphincter can lead to loss of bowel control (faecal incontinence). For people whose cancer has not spread, therapy treats many rectal cancers, with 70% or more of people living for more than 5 years.

Diseases of the anus – fecal incontinence

Stool incontinence may occur briefly during bouts of diarrhea or when hard stools get stuck in the rectum (stools). Persistent fecal incontinence can occur in people who have anal or spinal cord injuries, rectal prolapse (protrusion of the rectal mucosa through the anus), neurological damage from diabetes, anal tumors, or a pelvic injury during childbirth.

The doctor examines the person for any structural or neurological abnormalities. This examination includes an examination of the anus and rectum, checking the degree of sensation around the anus, and usually performing a sigmoidoscopy. Other tests, including an ultrasound of the anal sphincter, magnetic resonance imaging (MRI) of the pelvis and perineal area, tests of the function of the nerves and muscles that line the pelvis, and rectal and rectal pressure readings (anorectal manometry) may also be needed.

The first step in correcting stool incontinence is to try to establish a regular bowel pattern that results in a well-formed stool. Diet changes, including adding a small amount of fiber, often help. If these changes don’t help, a drug that slows down bowel movement, such as loperamide, may be effective.

Exercising the anal muscles (sphincters) by squeezing and releasing them increases their tone and strength. If faecal incontinence persists, surgery may be helpful, for example if the cause is an anal trauma or an anatomy. As a last resort, a colostomy (the surgical creation of an opening between the large intestine and the abdominal wall) may be performed. The anus is sewn up and the stool is led into a removable plastic bag attached to an opening in the abdominal wall.

See also: Why is it worth examining feces?

Anal diseases – levator syndrome

Paroxysmal anal pain (proctalgia fugax) is a temporary pain in the rectum. Coccidia is pain in the coccyx area. Both of these disorders are variants of levator ani syndrome.

Muscle spasm causes pain that is usually not related to bowel movements. Pain usually lasts less than 20 minutes. It can be short and intense, or it can be indistinct. It can occur spontaneously or while sitting, and can awaken a person from sleep. The pain may appear to be relieved by passing gas or defecating. In severe cases, the pain may last for hours and recur frequently.

The doctor performs a physical examination to rule out other painful anal conditions (such as hemorrhoids, fissures, or abscesses). Often, a physical examination may not reveal anything unusual, but the muscle may be tender or tense. Sometimes the pain is caused by a lower back or prostate disorder.

Pain episodes can be relieved by passing gas or a bowel movement, or by using a mild pain reliever (such as aspirin). Pain can also be relieved by soaking your anus in warm (not hot) water in a so-called sitz bath. Soaking is done by squatting or sitting for 10 to 15 minutes in a partially filled tub, or by using a container filled with warm water placed on the toilet bowl. When the symptoms of levator syndrome are more intense, patients can undergo pelvic physical therapy.

See also: What is the root of the pain in the anus?

Anal diseases – perianal infections

Hair around the anus and coccyx can burrow beneath the surface and cause an infection called a hair cyst (pilonidal cyst). It can appear as an abscess in this area just below the tailbone or as small drainage holes. Usually, surgery is needed to treat this condition.

STDs that can affect the anus include herpes, AIDS, chlamydia, and gonorrhea. Anal warts are small growths on the skin of the anus that look like little pink cauliflower and are caused by a virus (HPV).

See also: Embarrassing diseases of the anus

Anus – diagnosis of diseases of the anus

To diagnose an anal disorder, your doctor examines the skin around the anus for any abnormalities. The doctor examines the anus with a gloved finger. For women, this is often done in conjunction with a manual vaginal examination (gynecological examination). Doctors also frequently examine the abdomen.

The doctor then looks into the anus and rectum with a stiff tube (anoscope or proctoscope) about 7 to 25 centimeters in diameter. A longer, flexible tube (sigmoidoscope) can then be inserted so that the doctor can observe up to 60 cm or more of the colon.

An anoscopy or sigmoidoscopy (endoscopy) is generally uncomfortable but not painful. However, if the anal area is painful due to an abnormal condition, your doctor may apply an anesthetic (such as lidocaine) or local or even general anesthesia prior to testing. Sometimes a cleansing enema is given before sigmoidoscopy to clear stools from the lower colon.

Tissue and stool samples for microscopic examination and cultures can be obtained by sigmoidoscopy. Computed tomography or magnetic resonance imaging can also be performed.

Anus – prophylaxis and hygiene of the anus

Ways of dealing with and preventing rectal problems include hygiene and proper toilet habits.

Rectal hygiene includes the following tips.

1. Keep the anus clean by washing it with water every day. Do not use soaps as they reduce the natural oils that protect the anus and can cause dry and itchy anal areas. Instead, use a water-based cream or a soap-free cleanser.
2. Avoid rubbing the anus vigorously with toilet paper, as this can cause further skin abrasions that can become inflamed or infected.
3. Avoid cleaning wipes or chemicals.

Proper toilet practices prevent many diseases of the anus.

1. Let’s not put off the urge to go to the toilet.
2. Try not to overexert yourself when going to the toilet, as this can irritate the anal area and lead to serious complications. Let’s not sit on the toilet for more than a few minutes.

You can alleviate rectal discomfort by following these tips.

1. To ease anal pain and discomfort, let’s sit in a shallow bath with warm water for 10 to 20 minutes, several times a day if possible.
2. If the anal area is extremely painful and swollen, a cold compress or ice packs, such as a bag of frozen peas wrapped in a clean towel, can be used to relieve the pain and swelling. We should not keep a cold compress on this area for more than 30 minutes.
3. Over-the-counter creams, lotions, and ointments can also relieve itching around the anus. Follow the instructions attached to the preparations or ask a pharmacist for advice.

If you have anal pain, check with your doctor and ask about painkillers that you can take.

It’s worth adding that drinking plenty of water and eating high-fiber foods such as bran cereals, fruits and vegetables, and whole grain bread will help soften your stools, which can help prevent rectal problems.

See also: If it weren’t for the Chinese, it wouldn’t be hanging in our bathrooms. A brief history of toilet paper

Anus and sex

The anus has a relatively high concentration of nerve endings and can be an erogenous zone, which can make anal intercourse pleasant if done correctly. The vulva nerve, which branches to supply the external anal sphincter, also branches to the dorsal clitoral nerve and the dorsal penile nerve.

In addition to nerve endings, the pleasure of anal intercourse can be aided by close proximity to the anus and prostate in men, and by the vagina, clitoris and anal area in women. This is due to indirect stimulation of the prostate and vagina or clitoris. For the male partner introducing the penis, the pressure of the anus can be a source of pleasure by applying pressure to the penis.

Anal pleasure can also be achieved through anal masturbation, fingering, rimming, an activity called anilingus, and other penetrating and non-penetrating activities. Anal stretching or fisting is a pleasure for some, but poses a more serious risk of injury due to deliberate stretching of the anal tissues; his injuries include rupture of the anal sphincter and rectal and sigmoid perforation, which may result in death. Lubricant and condoms are commonly considered essential when engaging in anal sex, as is slow and careful penetration.

See also: What is anal sex?