The purpose of this project is to study the the efficacy and safety of probiotics implantation through infusion during colonoscopy in the treatment of functional constipation and irritable bowel syndrome. The study is a single-center, prospective, randomized, single-blind, controlled, cohort study. The invesitigators plan to enroll 80 patients with functional constipation and 80 patients with irritable bowel syndrome. The invesitigators will randomize the included study subjects. The experimental group receive basic treatment and a single infusion of probiotics through colonoscopy. The control group receive basic treatment and a single injection of normal saline through colonoscopy. The invesitigators will follow up the patients for 8-12 weeks. The primary endpoint is the efficacy of the single colonoscopic probiotics infusion in functional constipation and irritable bowel syndrome patients. The secondary endpoint is the safety of the single colonoscopic probiotics infusion in functional constipation and irritable bowel syndrome patients. Other exploratory objectives include the alterations in clinical indicators, fecal microbiota, and intestinal microbiota metabolites in feces and serum.

Inclusion Criteria:

• Patients undergoing for colonoscopy
• Meet Rome IV diagnostic criteria for functional constipation or irritable bowel syndrome
• Voluntarily participate in this clinical study and sign the informed consent.

Exclusion Criteria:

• Use of probiotics or antibiotics within the past 4 weeks
• History of intestinal surgery
• History of severe liver and kidney disease
• History of cardiovascular and cerebrovascular diseases
• History of neuropsychiatric diseases
• Pregnant women or lactating women
• Allergic to any ingredients of the live bacteria tablet