What is an anal abscess (paraproctitis)? Symptoms, causes and dangers

The rectum sits in the pelvis and is surrounded by fatty tissue on all sides. Inflammation of the lining of the bowel is called proctitis. When the inflammation spreads to the fatty tissue around the bowel, the condition is called paraproctitis: in Greek, "para" means "beside, around."

A closed cavity filled with pus is called an abscess in medicine. That is why acute paraproctitis is also called an anal or anorectal abscess. A perianal abscess is its most common form: it sits right next to the anus, under the skin, and can be seen with the eye. In everyday speech, these terms are often used to mean the same thing, and patients simply call the condition "a boil next to the anus."

So how does an abscess form? In the wall of the anal canal there are small glands that produce mucus. Their ducts open into the inside of the bowel. When a duct becomes blocked, germs multiply inside the gland and pus forms. The pus looks for a way out: it moves between the fibers of the sphincter (the ring-shaped muscle that closes the anal canal) downward toward the skin or upward into the deeper layers.

Types of abscess: superficial and deep

Depending on the direction the pus takes, an abscess can be in different places:

• perianal abscess: at the edge of the anus, under the skin; the most common and easiest to recognize;
• ischiorectal abscess: in the fatty tissue between the sitting bone and the rectum; usually larger;
• intersphincteric abscess: between the internal and external sphincter; hard to see from the outside but causes severe pain;
• supralevator abscess: deep, above the pelvic floor muscles; fever and a feeling of heaviness in the rectum stand out;
• horseshoe abscess: occurs when pus spreads from behind the anus to both sides.

In short, the deeper the abscess, the harder it is to recognize from the outside. That is why you should pay attention not only to a visible swelling but also to your general condition.

Often paraproctitis has no clear external cause: an anal gland simply becomes infected. But some conditions raise the risk:

1. Anal fissure. A fissure that stays open can be an entry point for infection. In some cases, it goes in a chain: fissure → abscess → fistula. Recognizing the symptoms of an anal fissure in time helps break this chain at the start.
2. Constipation and diarrhea. Hard stool damages the lining of the anal canal, and frequently repeated diarrhea irritates it.
3. Proctitis and inflammatory bowel disease. Untreated proctitis, as well as Crohn's disease, can cause an abscess and a fistula.
4. Injuries. Perineal tears during childbirth, trauma to the anal area, earlier operations.
5. Weak immunity. Diabetes and medications that weaken the immune system make it easier for an infection to become severe.

An anal abscess occurs most often between ages 20 and 60, and it is seen about twice as often in men as in women. Children are not exempt: in our practice, there was a case in which constipation that started with intestinal worms led first to an anal fissure and then to an abscess and a fistula.

At our clinic, we have met this scenario many times: an anal fissure is not shown to a doctor, is "treated" at home with ointment and after a while turns into a large abscess. One of our patients, a woman in her mid-fifties, developed a horseshoe abscess from a fissure that was not treated in time: the pus had collected around the muscles and the rectum. Putting off treatment of a small problem makes it bigger. Every patient's situation is individual.

The signs of a perianal abscess usually build up over a few days:

• throbbing pain next to the anus that keeps getting stronger; it gets worse when sitting, walking, coughing and on the toilet;
• swelling, redness and warmth to the touch around the anus;
• a painful, hard lump you can feel with your hand;
• fever, chills and weakness;
• with deep abscesses, a feeling of heaviness in the rectum, pain spreading to the buttock or tailbone, difficulty urinating; a swelling may not be visible from the outside;
• when the abscess bursts on its own, a discharge of pus or blood comes out and the pain suddenly eases.

The last sign misleads many people. When the pus drains, the pain lets up and a person thinks the illness has passed. In fact, the source of inflammation is still there and often turns into a fistula.

A painful lump next to the anus also needs to be told apart from other conditions. Paraproctitis is most often confused with a thrombosed hemorrhoid:

An acute anal fissure and a skin cyst can cause similar pain. The table only gives direction; an examination shows the exact difference.

Can anal itching be related to paraproctitis?

Sometimes, yes. In an acute abscess, pain is in the foreground, but in the chronic stage, when a fistula has formed, constant moisture and a pus-like discharge around the anus irritate the skin and cause itching and burning. Anal itching has other causes too:

• hemorrhoids and anal fissure: inflammation of the lumps and leakage from the fissure irritate the skin;
• fungal and bacterial infections: they develop in the presence of moisture;
• intestinal worms, especially pinworms: the itching gets worse at night;
• poor hygiene: too much soap and scented toilet paper damage the protective layer of the skin.

Treating itching as a simple skin problem and "silencing" it with a pharmacy cream hides the cause. If a pus-like or bloody discharge, pain and swelling come along with the itching, see a proctologist.

Paraproctitis is not a condition that can wait. If you have any of these signs, don't wait; seek urgent care:

• a fever or chills along with a painful swelling next to the anus;
• pain that grows hour by hour and you can't sit or lie down;
• urinating has become difficult or has stopped completely;
• redness spreads to the perineum, buttocks, testicles or labia, and the skin turns dark;
• you have diabetes or are receiving treatment that weakens your immune system.

If your temperature is high and you also have severe weakness, a racing heart or clouded consciousness, go to the emergency department of the nearest hospital without losing time.

If your complaints are milder, for example a small opening next to the anus with an occasional discharge, itching or moisture that bothers you, this is not an emergency. But don't put off a planned examination: it can be a sign of a fistula.

What can you do before seeing a doctor?

• A warm sitz bath may ease the pain a little, but it doesn't heal the abscess.
• Don't squeeze or pierce the abscess, and don't put ointment or a hot compress on it and wait for it to "ripen."
• Don't start antibiotics without a doctor's prescription: medication can mask the symptoms for a while and make the diagnosis harder.
• Make a note of the medications you take, especially blood thinners and diabetes medication, and tell your doctor at the examination.

The most common mistake is to try to "dissolve" an abscess with antibiotics. Antibiotics reach the tissues through the blood, but they don't get enough into a cavity that is filled with pus and surrounded by a wall. The fever may drop for a while, but the pus stays in place and looks for new paths.

Waiting creates these dangers:

• the pus spreading into deeper layers and to the other side of the anus;
• damage to the sphincter, which can later cause difficulty holding in gas and stool;
• the abscess turning into a fistula;
• in rare cases, especially in people with diabetes and weak immunity, a life-threatening infection with tissue death.

That is why the main treatment for an abscess is to open it surgically and drain the pus; this is called drainage. When needed, antibiotics are given alongside surgery as a supporting medication, for example, if the infection has spread or the patient has diabetes.

Once an abscess is found, it must be opened without delay: the operation is done under anesthesia, the pus is drained and the wound is followed with dressings and check-ups until it has healed completely. If a fistula is found, its treatment is planned separately. You can read detailed information about the course of the operation, fistula methods and the recovery period on our page on treatment of anal abscess and fistula.

An anal abscess and an anal fistula are two stages of the same disease: the abscess is the acute form and the fistula is the chronic form. After an abscess is opened or bursts on its own, in some patients the path the pus took does not close. A thin channel remains between the opening inside the bowel and the opening next to the anus. This is an anal fistula.

You can recognize a fistula by these signs:

• a small opening next to the anus and an occasional discharge of pus or blood from it;
• moisture, soiled underwear, an unpleasant smell;
• skin irritation and itching;
• when the opening closes, swelling and pain come back.

A fistula does not heal on its own and can branch over time. Its treatment is surgical, and the method is chosen according to how the fistula relates to the sphincter. When an operation is planned, preserving the sphincter, and with it the ability to hold stool, comes first.

• Treat an anal fissure and hemorrhoids in time.
• Prevent constipation: drink about 1.5–2 liters of fluid a day, mostly water (unless your doctor has told you otherwise), eat fiber-rich food and stay active.
• Warm water is enough for hygiene: after washing, pat the skin dry gently, and avoid too much soap and scented paper.
• If you have diabetes, keep your blood sugar under control.
• Don't buy suppositories, ointments and antibiotics at the pharmacy on your own.
• If you have had an abscess once, come for a follow-up examination after it heals; if abscesses keep coming back, the cause must be investigated.