This is a repository copy of Clostridium difficile infection. The article discusses the pathogenesis, epidemiology, mechanisms, diagnosis, and management of Clostridium difficile infection (CDI). CDI is caused by the Gram-positive bacterium Clostridium difficile, which is a leading cause of healthcare-associated diarrhoea. The infection is transmitted via the oral-faecal route and is associated with antibiotic use, which disrupts the gut microbiota. The primary virulence factors are the large clostridial toxins TcdA and TcdB, which cause inflammation, tissue necrosis, and diarrhoea. The article also discusses the binary toxin CDT, which is produced by some strains and may contribute to disease severity. The article outlines the epidemiology of CDI, noting that it is increasingly recognized as a cause of community-associated diarrhoea. Diagnosis involves detecting toxins or the presence of the bacterium in stool samples. Management includes antimicrobial therapy with metronidazole, vancomycin, or fidaxomicin, and in severe cases, surgery. Infection control measures are essential to prevent the spread of C. difficile, including isolation of infected patients and environmental decontamination. The article also discusses asymptomatic carriage of C. difficile, which can occur in both healthcare and community settings, and the role of the gut microbiota in disease development. Overall, the article provides a comprehensive overview of CDI, including its pathogenesis, diagnosis, and management.This is a repository copy of Clostridium difficile infection. The article discusses the pathogenesis, epidemiology, mechanisms, diagnosis, and management of Clostridium difficile infection (CDI). CDI is caused by the Gram-positive bacterium Clostridium difficile, which is a leading cause of healthcare-associated diarrhoea. The infection is transmitted via the oral-faecal route and is associated with antibiotic use, which disrupts the gut microbiota. The primary virulence factors are the large clostridial toxins TcdA and TcdB, which cause inflammation, tissue necrosis, and diarrhoea. The article also discusses the binary toxin CDT, which is produced by some strains and may contribute to disease severity. The article outlines the epidemiology of CDI, noting that it is increasingly recognized as a cause of community-associated diarrhoea. Diagnosis involves detecting toxins or the presence of the bacterium in stool samples. Management includes antimicrobial therapy with metronidazole, vancomycin, or fidaxomicin, and in severe cases, surgery. Infection control measures are essential to prevent the spread of C. difficile, including isolation of infected patients and environmental decontamination. The article also discusses asymptomatic carriage of C. difficile, which can occur in both healthcare and community settings, and the role of the gut microbiota in disease development. Overall, the article provides a comprehensive overview of CDI, including its pathogenesis, diagnosis, and management.