Most people have constant abdominal pain and a fever.
Computed tomography or another imaging test can distinguish an abscess from other problems.
Treatment involves draining pus from the abscess and taking antibiotics.
(See also Acute Abdominal Pain Overview of Gastrointestinal Emergencies Certain gastrointestinal disorders can be life threatening and require emergency treatment. For many people, emergency treatment involves surgery. Abdominal pain, often severe, usually accompanies... read more .)
Abdominal abscesses may form below the diaphragm, in the middle of the abdomen, in the pelvis, or behind the abdominal cavity. Abscesses also may form in or around any abdominal organ, such as the kidneys, spleen, pancreas, or liver, or in the prostate gland. Untreated abscesses can grow and damage nearby blood vessels and organs.
Sometimes, bacteria enter the bloodstream (sepsis Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more ) and spread to distant organs and tissues. Such spread can be fatal.
The Digestive System
Causes of Abdominal Abscesses
More common causes of abdominal abscesses involve spread of infection or inflammation caused by conditions such as appendicitis Appendicitis Appendicitis is inflammation and infection of the appendix. Often a blockage inside the appendix causes the appendix to become inflamed and infected. Abdominal pain, nausea, and fever are common... read more , diverticulitis Diverticulitis Diverticulitis is inflammation of one or more balloon-like sacs (diverticula). Infection may or may not develop. Diverticulitis usually affects the large intestine (colon). Left lower abdominal... read more , Crohn disease Crohn Disease Crohn disease is an inflammatory bowel disease where chronic inflammation typically involves the lower part of the small intestine, the large intestine, or both and may affect any part of the... read more , pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more , or pelvic inflammatory disease Pelvic Inflammatory Disease (PID) Pelvic inflammatory disease is an infection of the upper female reproductive organs (the cervix, uterus, fallopian tubes, and ovaries). Pelvic inflammatory disease is often caused by a sexually... read more .
Sometimes, abdominal abscesses are caused by perforation of the intestine Perforation of the Digestive Tract Any of the hollow digestive organs may become perforated (punctured), which causes a release of intestinal contents and can lead to sepsis (a life-threatening infection of the bloodstream) and... read more due to cancer, ulcer, or injury, and sometimes abscesses form after injury to the abdomen or after surgery on the abdomen.
Symptoms of Abdominal Abscesses
Specific symptoms of abdominal abscesses depend on the location of the abscess, but most people have constant discomfort or pain, feel generally sick (malaise), and often have a fever. Other symptoms include nausea, loss of appetite, and weight loss.
An abscess below the diaphragm may form when infected fluid, for example, from a ruptured appendix, is moved upward by the pressure of abdominal organs and by the suction created when the diaphragm moves during breathing. Symptoms may include a cough, painful breathing, chest pain, and pain in one shoulder. In this instance, the pain felt in one shoulder is an example of referred pain (pain felt in one area of the body that does not accurately represent where the problem is). Referred pain occurs because the shoulder and the diaphragm share the same nerves, and the brain incorrectly interprets the source of the pain (see figure ).
Abscesses in the mid-abdomen may result from a ruptured appendix, a ruptured intestine, inflammatory bowel disease Overview of Inflammatory Bowel Disease (IBD) In inflammatory bowel diseases, the intestine (bowel) becomes inflamed, often causing recurring abdominal pain and diarrhea. The 2 primary types of inflammatory bowel disease (IBD) are Crohn... read more , diverticular disease Definition of Diverticular Disease Diverticular disease is characterized by small, balloon-like sacs (diverticula) protruding through the layers of particular structures in the gastrointestinal tract (digestive tract). A single... read more , or an abdominal wound. The abdomen is usually painful in the area of the abscess.
An abscess in the lower abdomen may track down into the thigh or the area around the rectum (called the perirectal fossa).
Pelvic abscesses can result from the same disorders that cause abscesses in the mid-abdomen or from gynecologic infections. Symptoms may include abdominal pain, diarrhea caused by intestinal irritation, and an urgent or frequent need to urinate caused by bladder irritation.
Abscesses behind the abdominal cavity (called retroperitoneal abscesses) lie behind the peritoneum, the membrane that lines the abdominal cavity and organs. The causes, which are similar to those of abscesses in the abdomen, include inflammation and infection of the appendix (appendicitis Appendicitis Appendicitis is inflammation and infection of the appendix. Often a blockage inside the appendix causes the appendix to become inflamed and infected. Abdominal pain, nausea, and fever are common... read more ), the pancreas (pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more ), and the kidneys (the kidneys are located behind the abdominal cavity). Pain, usually in the lower back, worsens when the person moves the leg at the hip.
Abscesses of the pancreas, although rare, typically form after an attack of acute pancreatitis Acute Pancreatitis Acute pancreatitis is sudden inflammation of the pancreas that may be mild or life threatening but usually subsides. Gallstones and alcohol abuse are the main causes of acute pancreatitis. Severe... read more . Symptoms such as fever, abdominal pain, nausea, and vomiting often begin a week or more after a person recovers from pancreatitis.
Liver abscesses may be caused by bacteria or by amebas (single-celled, microscopic parasites). Bacteria can reach the liver from an infected gallbladder, a penetrating or blunt wound, an infection in the abdomen (such as a nearby abscess), or an infection carried by the bloodstream from elsewhere in the body. Amebas Amebiasis Amebiasis is an infection of the large intestine and sometimes the liver and other organs that is caused by the single-celled protozoan parasite Entamoeba histolytica, an ameba. The amebas... read more from an intestinal infection reach the liver through the blood vessels. Symptoms of liver abscesses include loss of appetite, nausea, and a fever. A person may or may not have abdominal pain.
Abscesses in the spleen are caused by an infection traveling through the bloodstream to the spleen, by an injury to the spleen, or by the spread of an infection from a nearby abscess, such as one below the diaphragm. Pain may occur in the left side of the abdomen, the back, or the left shoulder.
Diagnosis of Abdominal Abscesses
Doctors can easily misdiagnose an abscess because the first symptoms it causes are usually vague and mild and may be mistaken for less serious problems that are more common.
If doctors suspect a person has an abscess, they usually do computed tomography Computed Tomography and Magnetic Resonance Imaging of the Digestive Tract Computed tomography (CT) and magnetic resonance imaging (MRI) scans are good tests for assessing the size and location of abdominal organs. Additionally, cancerous (malignant) or noncancerous... read more (CT) of the abdomen and pelvis or sometimes ultrasound scanning Ultrasound Scanning (Ultrasonography) of the Abdomen Ultrasound scanning uses sound waves to produce pictures of internal organs (see also Ultrasonography). An ultrasound scan can show the size and shape of many organs, such as the liver and pancreas... read more (ultrasonography), x-rays X-Rays X-rays are a type of medical imaging that use very low-dose radiation waves to take pictures of bones and soft tissues. X-rays may be used alone (conventional x-ray imaging) or combined with... read more of the abdomen and chest, or magnetic resonance imaging Computed Tomography and Magnetic Resonance Imaging of the Digestive Tract Computed tomography (CT) and magnetic resonance imaging (MRI) scans are good tests for assessing the size and location of abdominal organs. Additionally, cancerous (malignant) or noncancerous... read more (MRI). These tests can help distinguish an abscess from other problems, as well as determine the source, size, and position of an abscess.
To make a definitive diagnosis and treat the abscess, doctors sometimes insert a needle through the skin to draw a sample of pus from the abscess (needle aspiration) and place a drain. To guide the placement of the needle, doctors use CT or ultrasound scanning. The sample of fluid is then examined in a laboratory to identify the infecting organism so that the most effective antibiotic can be selected.
Occasionally, radionuclide scanning Radionuclide Scanning Radionuclide scanning is a type of medical imaging that produces images by detecting radiation after a radioactive material is administered. During a radionuclide scan, a small amount of a radionuclide... read more is done to help identify abscesses. For scanning, a radionuclide is used to label a substance that accumulates in a specific part of the body. Different substances are used depending on which part of the body is to be evaluated.
Treatment of Abdominal Abscesses
Drainage of pus
Almost all abdominal abscesses need to be drained of pus, either by surgery or by a needle and a small flexible tube (catheter). To guide the placement of the needle and catheter, a doctor uses CT or ultrasound scanning. Once the doctor is sure the needle and catheter have reached the abscess, the needle is taken out but the catheter is left in place. The pus drains out through the catheter, usually over several days to weeks.
Antibiotics are usually used in addition to drainage to prevent the infection from spreading and to help completely eliminate the infection. Laboratory analysis of the pus identifies the infecting organism so that the most effective antibiotic can be selected. It is uncommon for antibiotics to cure an abscess without drainage.
If the abscess cannot be reached safely by the needle and catheter, surgical drainage may be necessary. Once the abscess has been drained, the source of the infection is also surgically treated. For example, if the abscess is caused by a perforation (hole) in the colon, doctors usually remove that part of the colon.
Maintaining proper nutrition is important. If people are unable to eat because of the abscess or because of the cause of the abscess, they may receive nutrition through a tube (called enteral tube nutrition Tube Feeding Tube feeding may be used to feed people whose digestive tract is functioning normally but who cannot eat enough to meet their nutritional needs. Such people include those with the following... read more ) or a vein (called parenteral nutrition Intravenous Feeding Intravenous feeding is used when the digestive tract cannot adequately absorb nutrients, as occurs in severe malabsorption disorders. It is also used when the digestive tract must be temporarily... read more ).
Prognosis for Abdominal Abscesses
Abdominal abscesses can cause death in about 10 to 40% of people. What caused the abscess and a person's general medical condition affect the prognosis more than the specific nature and location of the abscess. People who develop sepsis Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more have a worse prognosis.