What is an intra-abdominal abscess?

An intra-abdominal abscess is a collection of pus or infected fluid that is surrounded by inflamed tissue inside the belly. It can involve any abdominal organ. Or it can settle in the folds of the bowel.

What causes an intra-abdominal abscess?

Intra-abdominal abscesses sometimes happen because of another condition. An example might be appendicitis or diverticulitis. But, some cases happen as a complication after surgery. 

Abdominal abscesses can be caused by a bacterial infection. The most common bacteria to cause them are found in the stomach and intestines. One of these is Escherichia coli (E. coli). If left untreated, the bacteria will multiply. They can cause inflammation and kill healthy tissue.

Who is at risk for an intra-abdominal abscess?

Abdominal surgery or trauma can put you at risk for an intra-abdominal abscess. Additional concerns are health problems like diabetes or inflammatory bowel disease (IBD).

What are the symptoms of an intra-abdominal abscess?

If you've recently had surgery or trauma to an abdominal organ and have other risk factors, such as diabetes or inflammatory bowel disease, watch for signs of an intra-abdominal abscess.

Common symptoms include:

• Fever

• Belly pain

• Chest pain or shoulder pain 

• Lack of appetite

• Nausea and vomiting

• Change in bowel movements

• Rectal tenderness or fullness

• Mass in the belly

• Malnourishment

How is an intra-abdominal abscess diagnosed?

If you have symptoms of an intra-abdominal abscess, your healthcare provider may order these tests:

• Blood tests. Blood may be drawn to look for signs of infection or an abscess. Very useful tests are those that look at the number of white blood cells and other signs of inflammation.

• Imaging tests. The best imaging test to check for an abscess is usually a CT scan of the belly. Other tests, such as ultrasound or MRI, may be used as well.

• Physical exam. As part of your exam, your healthcare provider will take your temperature. They will also check for tenderness in the belly. Sometimes, the abscess can be felt as a mass in the midsection.

How is an intra-abdominal abscess treated?

An abscess will often need to be drained of fluid to heal. Most of the time antibiotics are given when an abscess is drained. The type of antibiotic will depend on how bad your abscess is, your age, and any other health-related concerns you may have.

One way to remove fluid is through percutaneous drainage. Your healthcare provider guides a needle through the skin to the place where the infection is. This is a short procedure. You will be given a a local anesthetic, and sedative if needed, to help you relax and not feel pain while it is being done. 

Another way to drain the abscess is with surgery. Surgery may also involve fixing the condition that caused the abscess in the first place, such as a bowel perforation. Sometimes, more than one operation is needed.

Many times, a drainage catheter is left in the abscess cavity after it is drained. Your healthcare team will check it and remove it when needed.

Your outcome will depend on the cause of your infection and how quickly you received treatment. Early treatment can greatly improve the outcome for people who have an intra-abdominal abscesses.

While you are being treated for an abscess, you may need nutritional support. This can be done by placing a feeding tube.

When should I call my healthcare provider?

Call your healthcare provider right away if you:

• Have a fever of 100.4°F (38°C), or as instructed by your provider

• Have belly pain

• Have nausea or vomiting

• Have other new symptoms

• Are at high risk for an infection because you:

  • Have other risk factors, such as diabetes or inflammatory bowel disease

  • Smoke

  • Had recent surgery or medical procedure

Key points about an intra-abdominal abscess

• An intra-abdominal abscess is a collection of pus or infected fluid that is surrounded by inflamed tissue inside the belly.

• An intra-abdominal abscess may be caused by bacteria. If left untreated, the bacteria will multiply. This can cause inflammation and kill healthy tissue.

• If you've recently had surgery or trauma to an abdominal organ and have other risk factors, such as diabetes or inflammatory bowel disease, watch for signs of an abscess.

• Early treatment can greatly improve the outcome for people who have intra-abdominal abscesses.

• During treatment and recovery, you may need to get nutrition through a feeding tube.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.