Biliary tract disorders (intra- and extrahepatic), infections within the portal drainage area (appendicitis, colonic diverticulitis, etc.), and hematogenous spread of bacteremia during systemic infections can be causative factors, but there are still many patients with liver abscesses that can be detected without significant predisposing factors, so-called cryptogenic liver abscesses. The most common causative organisms are gram-negative bacilli: Escherichia coli and Klebsiella; enterococci; microaerobic and anaerobic streptococci; Bacteroides fragilis and Clostridium difficile. Clinical and laboratory findings often lack specific diagnostic value for bacterial liver abscesses, and the key to diagnosis lies in suspecting the disease and trying to confirm the diagnosis. The following points can help to confirm the diagnosis: a. Fever, sometimes chills and high fever (85%-95%), mostly of rapid onset, accompanied by excessive sweating, nausea and loss of appetite. Pain in the right upper abdomen or right quarter rib area (84%-97%), mostly persistent dull pain or distension, may be accompanied by right shoulder involvement pain, right lower chest and liver percussion pain. The liver is enlarged (50% to 87%) with tenderness, and if the swelling is located in the superficial part of the liver edge, the right upper abdominal muscle tension and pressure pain may appear. B-type ultrasonography has a correct diagnostic rate of 70% to 100%, and can determine the location and number of abscesses, and can be clearly differentiated from solid intrahepatic occupations. It is also possible to diagnose and drain the abscess by percutaneous needle aspiration under its guidance, and to observe the efficacy of the treatment with follow-up. V. X-ray thoracoabdominal fluoroscopy: right lobe liver abscess (common, about 60%) can cause signs such as elevation of the right diaphragm, limitation of movement, right reactive pleurisy or pleural effusion and right lower lobe pulmonary atelectasis. Bacterial liver abscess should be differentiated from the following diseases: i. Amoebic liver abscess (see next section for details). Hepatocellular carcinoma: usually no fever and other signs of infection poisoning, hepatomegaly but hard texture, AFP measurement is often positive, ultrasound and CT examination are helpful to differentiate. B-type ultrasound can localize the abscess site. Treatment: I. Antibiotic treatment. For multiple small abscesses and before and after drainage of isolated and larger abscesses, as the causative agent is mostly a mixture of biliary or enteric-derived negative bacilli, anaerobic and aerobic bacteria, the antimicrobial agents of penicillin family, aminoglycosides or cephalosporins are generally applied, and metronidazole is added. Taking blood culture before applying antibiotics will be more helpful to the correct use of antibiotics, and the time of use can be based on the results of ultrasound detection, one week after the abscess disappears and the body temperature is normal. B. Ultrasound-guided percutaneous drainage. It is suitable for larger (>4.0cm) isolated abscesses deep in the liver parenchyma. Attention should be paid to avoid damaging intrahepatic vessels and bile ducts, and the drainage tube should not be too thick. Third, surgical drainage. It is suitable for patients with unremarkable effect of antibiotic treatment or the etiology of liver abscess requiring surgical treatment, such as purulent cholangitis, intrahepatic stones complicating liver abscess, and patients with isolated large abscesses located on the surface of liver that can be easily drained surgically. Care should still be taken to prevent contamination of the abdominal cavity at the time of surgery.