The duration of effectiveness of Saccharomyces boulardii Bulk varies from person to person and is mainly related to the patient’s condition and personal constitution. It is a biological antidiarrheal agent that can play an antitoxic, anti-microbial and mucosal nutritional role in the body and is not destroyed by the mucus of the gastrointestinal tract. It is commonly used clinically for the treatment of non-specific diarrhea in adults or children, and is also effective for diarrhea caused by dysbiosis of the intestinal flora. The effect time of Saccharomyces boulardii Bulk depends on the patient’s condition and personal constitution, and cannot be generalized. Patients with mild condition and good constitution will have fast effect, while those with severe condition and poor constitution will have slow effect, and there is no clear time point in the clinic. There is no definite time point in clinical practice. The population for taking Saccharomyces boulardii includes adults, children and infants, but the dosage for children and infants should be reduced accordingly.