What is an abdominal abscess?

An abscess is a pocket of inflamed tissue filled with pus. Abscesses can form anywhere on the body (both inside and outside). They’re most commonly found on the surface of the skin.

An abdominal abscess is a pocket of pus located in the abdomen.

Abdominal abscesses can form near the inside of the abdominal wall, at the back of the abdomen, or around organs in the abdomen, including the liver, pancreas, and kidneys. Abdominal abscesses may develop for no apparent reason, but they’re usually related to another event, such as intra-abdominal surgery, rupture of the bowel, or injury to the abdomen.

Abdominal abscesses are caused by bacteria that usually enter the abdomen as a result of penetrating trauma, rupture of the bowel, or intra-abdominal surgery. Intra-abdominal abscesses (abscesses within the abdomen) can develop when the abdominal cavity or an organ in the abdomen is compromised in some way and bacteria are able to enter. Such conditions include appendicitis, bowel rupture, penetrating trauma, surgery, and Crohn’s disease or ulcerative colitis. Depending on where the abdominal abscess is located, additional causes may be to blame.

Abscesses can also form in the space between the abdominal cavity and the spine. These abscesses are known as retroperitoneal abscesses. The retroperitoneum refers to the space between the abdominal cavity and the spine.

General symptoms of abdominal abscesses include:

  • feeling unwell
  • abdominal pain
  • nausea and vomiting
  • fever
  • loss of appetite

The symptoms of an abdominal abscess may be similar to the symptoms of other, less serious conditions. Your doctor may run an imaging test to make a proper diagnosis. An ultrasound may be the first diagnostic tool used. Other imaging tests, such as a CT scan or MRI, also help your doctor see the abdominal organs and tissues.


An abdominal ultrasound uses high-frequency sound waves to create images of organs in the abdomen.

During the test, you’ll lay on a table with your abdomen exposed. An ultrasound technician will apply a clear, water-based gel to the skin over the abdomen. Then they’ll wave a handheld tool called a transducer over the abdomen. The transducer sends out high-frequency sound waves that bounce off body structures and organs. The waves are sent to a computer, which uses the waves to create images. The images allow your doctor to closely examine organs in the abdomen.

Computerized tomography (CT) scan

A CT scan is a special X-ray that can show cross-sectional images of a specific area of the body.

The CT scanner looks like a large circle with a hole in the middle, called a gantry. During the scan, you’ll lay flat on a table, which is positioned in the gantry. The gantry then begins to rotate around you, taking images of your abdomen from many angles. This gives your doctor a complete view of the area.

A CT scan can display ruptures, localized abscesses, organs, abdominal growths, and foreign objects in the body.

Magnetic resonance imaging (MRI)

An MRI uses large magnets and radio waves to create images of the body. The MRI machine is a long magnetic tube.

During this test, you’ll lie on a bed that slides into the tube’s opening. The machine produces a magnetic field that surrounds your body and aligns water molecules in your body. This allows the machine to capture clear, cross-sectional images of your abdomen.

An MRI makes it easier for your doctor to check for abnormalities in the tissues and organs in the abdomen.

Abscess fluid sample analysis

Your doctor may take a sample of fluid from the abscess and examine it to make a better diagnosis. The method for obtaining a fluid sample depends on the location of the abscess.

Drainage is one of the first steps in treating an abdominal abscess. Needle drainage is one of the methods used to drain pus from an abscess.

During this procedure, your doctor will use a CT scan or ultrasound to insert a needle through your skin and directly into the abscess. Your doctor will then pull the plunger to remove all the fluid. After draining the abscess, your doctor will send a sample to the lab for analysis. This will help determine which antibiotics to prescribe.

You will also require intravenous antibiotics to treat the abdominal abscess.

Some cases may require surgery. Surgery may be necessary:

  • to clean out the abscess more thoroughly
  • if the abscess is difficult to reach with a needle
  • if an organ has ruptured

Your doctor will give you general anesthesia to put you to sleep throughout the surgery. During the procedure, the surgeon will make a cut in the abdomen and locate the abscess. They’ll then clean the abscess and attach a drain to it so pus can drain out. The drain will stay in place until the abscess heals. This usually takes several days or weeks.