An abscess is a collection of infected fluid and inflammatory debris that has been walled off by the body’s immune system. Any inflammatory process in the abdomen or pelvis such as appendicitis, diverticulitis, and Crohn’s disease, can lead to an abscess. Traumatic puncture wounds and foreign bodies can also result in abscess formation. Common locations for an abdominal abscess are the subphrenic and subhepatic spaces. Abscesses can also develop in organs, such as the liver (intrahepatic abscess) or kidney (renal abscess). An abscess must be promptly treated with antibiotics and either percutaneous or surgical drainage to prevent systemic infection or sepsis.