General Principles

  • Primary or spontaneous bacterial peritonitis (SBP) is a common complication of cirrhosis and ascites. M. tuberculosis and Neisseria gonorrhoeae (Fitz-Hugh–Curtis syndrome) also can occasionally cause primary peritonitis (see Chapter 16, Sexually Transmitted Infections, HIV, and AIDS). E. coli, Klebsiella pneumonia, and S. pneumoniae are common pathogens.
  • Secondary peritonitis may be caused by a perforated viscus in the gastrointestinal or genitourinary tract or contiguous spread from a visceral infection, usually resulting in an acute surgical abdomen.
  • Peritonitis related to peritoneal dialysis is addressed in Chapter 13, Renal Diseases.


Clinical Presentation

SBP may present with subtle abdominal symptoms without typical signs of infection. SBP should be ruled out with a diagnostic paracentesis in patients admitted with cirrhosis and ascites presenting with gastrointestinal bleeding, encephalopathy, acute kidney injury, or other decompensation of liver disease. Patients with secondary peritonitis may appear acutely ill with abdominal tenderness and peritoneal signs.

Diagnostic Testing

  • Send blood cultures and ascites fluid for culture (directly inoculate culture bottles at bedside), cell count, and differential. SBP is diagnosed when ascites fluid has >250 neutrophils/mm.1
  • Diagnosis of secondary peritonitis is made clinically and with imaging to evaluate for free air (perforation) and the source of infection. Blood cultures should be obtained.


  • First-line treatment typically includes either a third-generation cephalosporin (e.g., cefotaxime 2 g IV q8h) or a fluoroquinolone (e.g., ciprofloxacin 400 mg IV q12h). Administration of IV albumin on days 1 and 3 of treatment may improve survival.2
  • Treatment should be continued for 5 days. Extended courses may be needed for P. aeruginosa or resistant organisms.
  • SBP prophylaxis with a fluoroquinolone or TMP-SMX should be initiated after the first episode of SBP or after variceal bleeding.
  • Secondary peritonitis may require surgical intervention if there is perforation or intra-abdominal abscess formation. Antibiotics are continued until imaging demonstrates resolution of the abscess.
  • Treatment of chronic tuberculous peritonitis is the same as that of pulmonary tuberculosis.


  1. McDonald LC, Gerding DN, Johnson S, et al. Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clin Infect Dis. 2018;66(7):e1-e48.  [PMID:29462280]
  2. Runyon BA; AASLD. Introduction to the revised American Association for the Study of Liver Diseases Practice Guideline management of adult patients with ascites due to cirrhosis 2012. Hepatology. 2013;57(4):1651-1653.  [PMID:23463403]


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