Fengliao Changweikang for Diarrhea-predominant Irritable Bowel Syndrome: N-of-1 Trial
China50 participantsStarted 2025-11
Plain-language summary
Irritable bowel syndrome with diarrhea (IBS-D) is a functional gastrointestinal disorder, with characteristics of defecation related abdominal pain and diarrhea. Routine treatment strategy for IBS-D is symptom-based with unsatisfactory results, while there is a growing interest in complementary and alternative medicine such as Traditional Chinese Medicine. However, lack of high-quality evidences being the obstacle for its development.
This study aims to evaluate the efficacy of Fengliao Changweikang Keli (FLCWK) on symptoms and health-related quality of life in mild to moderate IBS-D patients.
After 2-week run-in period, each participant will be randomized to a sequence of six 4-week double-blind treatment periods of FLCWK 8 g three times daily or placebo, separated by 2-week washout periods.
Who can participate
Age range
18 Years – 75 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Aged between 18 and 75 years.
. Mild to moderate IBS-D patients, with IBS Severity Scoring System (IBS-SSS) scores of 75 to 300 points\[14\].
. Ability to complete questionnaires and provide written informed consent.
. Current use of IBS medications (probiotics, antibiotics, antispasmodic, antidiarrheal and neuromodulators) should be prescribed on a stable dose at least 30 days prior to enrollment, and have no plan to change the dose, diet or lifestyle.
. Normal blood cell count, liver function, creatinine and urea levels within the last 2 weeks.
Exclusion criteria
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
IBS-SSS score
Timeframe: At the end of run-in period (week 2) and at the end of each washout period (week 8, 14, 20, 26, 32) and during each treatment period (week 6, 12, 18, 24, 30, 36).