Background:Clostridium difficile(C. difficile) is a common cause of hospital-acquired diarrhea. It is associated with significantly higher mortality and morbidity in addition to the cost-effectiveness burden on the healthcare system. The primary risk factors forC. difficileinfection (CDI) are pastC. difficileexposure, proton pump inhibitors, and antibiotic usage. These risk factors are also associated with poor prognosis.Objective: This study was performed in Dr. Sulaiman Al Habib Tertiary Hospital in the Eastern Region of Saudi Arabia. The aim was to evaluate the risk and prognostic factors of CDI and their association with the outcomes of hospital stay, such as complications, length of stay (LOS), and treatment duration.Patients and methods: This is a retrospective cohort study for all patients who tested forC. difficilein the medical department. The target population was all adult patients ≥16 years with positive stool toxins forC. difficilebetween April 2019 and July 2022. The main outcome measures are risk and poor prognostic factors for CDI.Results:C. difficleinfection patients were included in the study; 12 (52.2%) were female, and 11 (47.8%) were male. The mean age of the patients was 58.3 (SD: 21.5) years; 13 (56.5%) patients were below 65 years, and 10 were above 65 years. Only four patients were without comorbidities, and 19 (82.6%) patients had various comorbidities. Importantly, hypertension was the most common comorbidity in 47.8% of the patients. Furthermore, advanced age significantly impacted the hospital LOS as the mean age among patients who stayed at the hospital less than four days and those who stayed ≥4 days was 49.08 (19.7) and 68.36 (19.5), respectively (P= .028).Conclusion: Advanced age was the most frequent poor prognostic factor among our inpatient participants with positive CDI. It was significantly associated with longer hospital LOS, more complications, and longer treatment duration.