Anorectal abscess
An anorectal abscess is a collection of pus in the area of the anus and rectum.
Causes
Common causes of anorectal abscess include:
- Blocked glands in the anal area
- Infection of an anal fissure
Anal fissure
An anal fissure is a small split or tear in the thin moist tissue (mucosa) lining the lower rectum (anus).
Read Article Now Book Mark Article - Sexually transmitted infection (STD)
- Trauma
Deep rectal abscesses may be caused by intestinal disorders such as Crohn disease or diverticulitis.
Crohn disease
Crohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...
Read Article Now Book Mark ArticleDiverticulitis
Diverticula are small, bulging sacs or pouches that form on the inner wall of the intestine. Diverticulitis occurs when these pouches become inflame...
Read Article Now Book Mark ArticleThe following factors increase the risk for an anorectal abscess:
- Anal sex
- Chemotherapy medicines used to treat cancer
Chemotherapy
The term chemotherapy is used to describe cancer-killing drugs. Chemotherapy may be used to:Cure the cancerShrink the cancerPrevent the cancer from ...
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Diabetes
Diabetes is a long-term (chronic) disease in which the body cannot regulate the amount of sugar in the blood.
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Inflammatory bowel disease (Crohn disease and ulcerative colitis)
Ulcerative colitis
Ulcerative colitis is a condition in which the lining of the large intestine (colon) and rectum become inflamed. It is a form of inflammatory bowel ...
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-
Weakened immune system (such as from HIV/AIDS)
HIV/AIDS
Human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). When a person becomes infected with HIV, the ...
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The condition affects men more than women. The condition may occur in infants and toddlers who are still in diapers and who have a history of anal fissures.
Symptoms
Common symptoms are swelling around the anus and a constant, throbbing pain with swelling. Pain may be severe with bowel movements, coughing and sitting.
Other symptoms may include:
- Constipation
Constipation
Constipation in infants and children means they have hard stools or have problems passing stools. A child may have pain while passing stools or may ...
Read Article Now Book Mark Article - Discharge of pus from the rectum or in the area of the anus
- Fatigue, fever, night sweats, and chills
Fever
Fever is the temporary increase in the body's temperature in response to a disease or illness. A child has a fever when the temperature is at or abov...
Read Article Now Book Mark Article - Redness, painful and hardened tissue in the area of the anus
- Tenderness
In infants, the abscess often appears as a swollen, red, tender lump at the edge of the anus. The infant may be fussy and irritable from discomfort. There are usually no other symptoms.
Exams and Tests
A rectal examination may confirm an anorectal abscess. A proctosigmoidoscopy may be done to check for other diseases.
Rectal examination
A digital rectal exam is an exam of the lower rectum. Your health care provider uses a gloved, lubricated finger to check for any abnormal findings....
Read Article Now Book Mark ArticleProctosigmoidoscopy
Sigmoidoscopy is a procedure used to see inside the sigmoid colon and rectum. The sigmoid colon is the area of the large intestine nearest to the re...
Read Article Now Book Mark ArticleIn some cases, a CT scan, MRI, or ultrasound is needed to help locate the collection of pus.
CT scan
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...
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A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...
Read Article Now Book Mark ArticleUltrasound
Ultrasound uses high-frequency sound waves to make images of organs and structures inside the body.
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The problem rarely goes away on its own. Antibiotics alone usually cannot treat an abscess.
Treatment involves surgery to open and drain the abscess.
- Surgery is usually done with local numbing medicine, along with medicine to make you sleepy. Sometimes, spinal or general anesthesia is used.
Medicine to make you sleepy
Conscious sedation is a combination of medicines to help you relax (a sedative) and to block pain (an anesthetic) during a medical or dental procedur...
Read Article Now Book Mark ArticleSpinal or general anesthesia
Spinal and epidural anesthesia are procedures that deliver medicines that numb parts of your body to block pain. They are given through shots in or ...
Read Article Now Book Mark Article - Surgery is most often an outpatient procedure, which means that you go home on the same day. The surgeon cuts open the abscess and drains the pus. Sometimes a drain is put in to keep the incision open and draining, and sometimes the abscess cavity is packed with gauze.
- If the pus collection is deep, you may need to stay in the hospital longer for pain control and nursing care of the abscess drainage site.
- After surgery, you may need warm sitz baths (sitting in a tub of warm water). This helps relieve pain and reduce swelling.
Sitz baths
A sitz bath is a warm water bath used for healing or cleansing purposes. You sit in the bath. The water covers only your hips and buttocks. The wa...
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Drained abscesses are usually left open and no stitches are needed.
The surgeon may prescribe painkillers and antibiotics.
Avoiding constipation will help decrease pain. You may need stool softeners. Drinking fluids and eating foods with lots of fiber can also help.
Outlook (Prognosis)
With prompt treatment, people with this condition usually do well. Infants and toddlers usually recover quickly.
Complications can occur when treatment is delayed.
Possible Complications
Complications of anorectal abscess may include:
- Anal fistula (abnormal connection between the anus and another structure)
Fistula
A fistula is an abnormal connection between two body parts, such as an organ or blood vessel and another structure. Fistulas are usually the result ...
Read Article Now Book Mark Article - Infection that spreads to the blood (sepsis)
Sepsis
Sepsis is an illness in which the body has a severe, inflammatory response to bacteria or other germs.
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- Problem keeps coming back (recurrence)
When to Contact a Medical Professional
Contact your health care provider if you:
- Notice rectal discharge, pain, or other symptoms of anorectal abscess
- Have fever, chills, or other new symptoms after being treated for this condition
- Have diabetes and your blood glucose becomes difficult to control
Prevention
Prevention or prompt treatment of STDs may prevent an anorectal abscess from forming. Use condoms during intercourse, including anal sex, to prevent such infections.
In infants and toddlers, frequent diaper changes and proper cleaning during diaper changes can help prevent both anal fissures and abscesses.
Reviewed By
Debra G. Wechter, MD, FACS, General Surgery Practice Specializing in Breast Cancer, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Coates WC. Anorectal procedures. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 45.
Hyman N, Umanskiy K. Anus. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. St Louis, MO: Elsevier; 2022:chap 53.