Extraintestinal Clostridium difficile infection presenting as spontaneous bacterial peritonitis

Clostridioides difficile (C. difficile) infections (CDIs) are typically intestinal but can also present extraintestinally, a rare occurrence with limited literature. This case describes a woman with cirrhosis who developed spontaneous bacterial peritonitis (SBP) caused by monomicrobial extraintestinal CDI, successfully treated with metronidazole. Despite no symptoms of infection, routine paracentesis revealed ascitic fluid indicative of SBP and subsequent cultures identified C. difficile Imaging ruled out secondary peritonitis, and she had no recent abdominal surgery or enteric symptoms. The literature suggests that extraintestinal CDI accounts for 0.17%-1.08% of CDIs, with most cases being polymicrobial and often associated with traditional risk factors like antibiotic exposure and hospitalisations. However, CDI-related SBP is exceedingly rare, with only 11 cases reported, primarily in men with cirrhosis. Treatment varies with poor prognosis and low recurrence rates. This case highlights the complexity and challenges in managing extraintestinal CDI.