This is a prospective, randomized, double-blind, placebo-controlled, parallel-group interventional clinical trial designed to evaluate the efficacy and safety of a Bacillus coagulans-based product in adult patients with mild to moderate Irritable Bowel Syndrome with predominant diarrhea (IBS-D), diagnosed according to Rome III criteria.
A total of 50 eligible male and female participants aged 18 to 65 years will be randomized in a 1:1 ratio to receive either Bacillus coagulans capsules or matching placebo for 8 weeks. The investigational product contains Bacillus coagulans (10⁶-10⁸ CFU) administered orally twice daily, morning and evening.
The primary objective is to assess the effect of the study product on IBS-D symptoms, including abdominal pain, gastrointestinal symptom severity, stool consistency, and stool frequency, using validated assessment tools such as Abdominal Pain Visual Analogue Scale (VAS), IBS Symptom Severity Scale (IBS-SSS), and Bristol Stool Form Scale (BSFS). Secondary assessments include changes in hematological parameters and lipid profile biomarkers, along with safety monitoring through vital signs and adverse event reporting.
Participants will attend four study visits: screening, baseline, Week 4, and Week 8. Weekly symptom recordings for abdominal pain and stool characteristics will be documented using participant diary cards throughout the treatment period.