Clostridioides difficile (C. difficile) colitis is a common hospital-acquired disease, which increases hospitalization length and the mortality rate. Moreover, refractory or recurrent C. difficile colitis is an emerging disease. The tapering course of oral vancomycin or oral fidaxomicin is current standard treatment for refractory or recurrent C. difficile colitis. Fecal microbiota transplantation (FMT) is an alternative one. However, the tapering course of oral vancomycin needs a 6- to 12-week duration, fidaxomicin is expensive, and FMT is not available in every hospital; therefore, it is needed to develop a new treatment. Evidence has shown that the disturbance with reduced diversity of intestinal microbiota may lead to refractory C. difficile colitis. Besides fecal microbiota transplantation, probiotics administration can also correct the disturbed intestinal microbiota. However, inconsistent efficacy of probiotic administration was reported, which may be attributed to the interference by the gastric acid. Precise delivery of probiotics into the colon by colonoscopy can avoid the destruction by gastric acid, with which a better treatment efficacy is expected. The best regimen for C. difficile colitis should be the one which succeeds on the first attempt. Therefore, this study is aimed toward validating the efficacy and safety of the colonoscopic probiotics-spray. Patients diagnosed with C. colitis will be enrolled. All patients will accept the standard treatment of oral vancomycin for 14 days. As an adjuvant probiotic administration at the same time, enrolled patients will be randomly assigned to the probiotics-spray (PS) group and the probiotics-oral (PO) group, respectively. The patients in the PS group will receive colonoscopic spray of probiotics once, while the patients in the PO group will receive the same dosage of oral probiotics divided into 5 days. This study will compare the difference in fecal microbiota changes between the colonoscopic probiotics-spray group and the probiotics-oral group. Moreover, this study will evaluate the efficacy and safety between the colonoscopic probiotics-spray and probiotics-oral in patients with C. difficile colitis.