Huanghou Zhixie Diwan in the Treatment of Irritable Bowel Syndrome With Diarrhea (IBS-D)

Randomized, Double-Blind, Placebo-Controlled, Multicenter Phase II Exploratory Clinical Study on the Efficacy and Safety of Huanghou Zhixie Diwan in the Treatment of Irritable Bowel Syndrome With Diarrhea (Large Intestinal Damp-heat)

This trial is a randomized, double-blind, placebo-controlled, parallel-group, multicenter Phase II clinical trial. Its purpose is to evaluate the efficacy and safety of Huanghou Zhixie Diwan in subjects with irritable bowel syndrome with diarrhea (Large Intestinal Damp-heat syndrome) after 4 weeks of treatment.

Study Overview

• Status: Not yet recruiting
• Conditions: Patients With Irritable Bowel Syndrome With Diarrhea
• Intervention / Treatment: Drug: Huanghou Zhixie Diwan group; Drug: Huanghou Zhixie Diwan mimic

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Yayun Zhang; Phone Number: +86-18251834682; Email: zhangyayun@lys.cn

Study Locations

• China
  • Beijing, China
    • Beijing Traditional Chinese Medicine Hospital, Capital Medical University
  • Changsha, China
    • The First Hospital of Hunan University of Chinese Medicine
  • Daqing, China
    • Daqing People's Hospital
  • Guangzhou, China
    • GuangDong Second Traditional Chinese Medicine Hospital
  • Hohhot, China
    • Inner Mongolia Hospital of Traditional Chinese Medicine
  • Lianyungang, China
    • Lianyungang Hospital of Traditional Chinese Medicine
  • Luoyang, China
    • Luoyang Third People's Hospital
  • Luoyang, China
    • Luoyang First People's Hospital
  • Meihekou, China
    • Meihekou Central Hospital
  • Shenyang, China
    • The Third Affiliated Hospital of Liaoning University of Traditional Chinese Medicine
  • Shijiazhuang, China
    • Hebei Provincial Hospital of Traditional Chinese Medicine
  • Tianjin, China
    • The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine
  • Wenzhou, China
    • Wenzhou TCM Hospital of Zhejiang Chinese Medical University
  • Xiamen, China
    • Xiamen Hospital of Traditional Chinese Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Aged from 18 to 65 years old, regardless of gender.
2. Meeting the Western medicine diagnostic criteria for IBS-D (Rome IV criteria).
3. Conforming to the TCM syndrome differentiation criteria for Large Intestinal Damp-heat.
4. During the run-in period, the weekly average score of abdominal pain is ≥ 3 points based on the 11-point (0-10) Numerical Rating Scale (NRS); and there are at least 2 days per week with stool consistency classified as Type 6 or Type 7 according to the Bristol Stool Scale.
5. The total score of the Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) at baseline is ≥ 175 points.
6. Colonoscopy performed within 12 months prior to the run-in period, and meeting one of the following conditions for enrollment:

1) Normal colonoscopy results with no organic lesions; 2) Abnormal colonoscopy findings such as hemorrhoids and intestinal polyps (diameter ≤ 5 mm, number ≤ 3), and assessed eligible for enrollment by the investigator; 3) Previous intestinal polyps with diameter > 5 mm or number > 3, which were treated endoscopically more than 6 months ago, with residual polyps of diameter ≤ 5 mm and number ≤ 3, and assessed eligible for enrollment by the investigator.

(7) Participants are fully conscious, free from mental illness or cognitive impairment, capable of understanding and completing scale assessments. All participants voluntarily agree to participate in this clinical trial, sign the informed consent form, and comply with all study protocol requirements throughout the trial.

Exclusion Criteria:

1. Patients diagnosed with irritable bowel syndrome classified as IBS-C, IBS-M or IBS-U.
2. Patients with a confirmed diagnosis of digestive system diseases in medical history or at screening, including peptic ulcer (excluding those with healed ulcers assessed by the investigator to have no impact on efficacy and safety evaluation), inflammatory bowel disease, intestinal tuberculosis, intestinal obstruction, intestinal adhesion, eosinophilic gastroenteritis, tuberculous peritonitis, liver cirrhosis, etc.
3. Patients with acute diarrhea and/or severe abdominal pain caused by other diseases within 1 month prior to screening, or those suffering from other diseases assessed by the investigator to interfere with efficacy evaluation and increase safety risks.
4. Patients with a history of abdominal surgery who may present symptoms similar to IBS as judged by the investigator (appendectomy and cesarean section are excluded).
5. Patients with a confirmed diagnosis of systemic diseases affecting gastrointestinal function in medical history or at screening, such as diabetes mellitus, hyperthyroidism or hypothyroidism, chronic renal insufficiency, autoimmune diseases (e.g. allergic enteritis, Henoch-Schönlein purpura, Behçet's syndrome, systemic lupus erythematosus), etc.
6. Patients complicated with other painful conditions such as arthritis and migraine that may interfere with Numeric Rating Scale (NRS) pain assessment; female patients with severe dysmenorrhea requiring analgesic medication.
7. Patients with malignant tumors within the past 5 years or diagnosed at screening.
8. Participants presenting gastrointestinal alarm symptoms within 14 days prior to screening, including hematochezia, positive fecal occult blood test, anemia, ascites, nocturnal diarrhea, unexplained weight loss or fever, etc., who are deemed ineligible for enrollment by the investigator.
9. Patients with severe diseases involving cardiovascular, cerebrovascular, hepatic, renal or other systems.
10. Patients who have undergone surgical operation within 30 days prior to screening, which is assessed by the investigator to affect safety or efficacy evaluation, or those scheduled to receive surgery during the study period.
11. Participants who have received medications or treatments for IBS within 4 weeks prior to randomization (e.g. antispasmodics, antidiarrheals, prokinetic agents, neurotransmitter regulators, intestinal flora modulators, traditional Chinese medicine, acupuncture and tuina).
12. Participants who have taken other drugs affecting gastrointestinal function within 4 weeks prior to randomization (e.g. anticholinergics, 5-Hydroxytryptamine 3 (5-HT3) receptor antagonists, antacids, antidepressants, anxiolytics, opioid receptor agonists, long-term or high-dose non-steroidal anti-inflammatory drugs, traditional Chinese herbal decoctions, etc.), or those who cannot discontinue such drugs during the trial.

13. Participants with abnormal liver and renal function test results at screening and baseline:

    1. Aspartate aminotransferase (AST) ≥ 1.5 times the Upper Limit of Normal (ULN);
    2. Alanine aminotransferase (ALT) ≥ 1.5 × ULN;
    3. Blood urea nitrogen (BUN) ≥ 1.5 × ULN; d) Serum creatinine > ULN.
14. Participants with treatment compliance < 80% or > 120% during the run-in period, or those who completed the run-in period diary cards for fewer than 5 days per week.
15. Participants who took rescue medication (pinaverium bromide) continuously or intermittently for more than 2 days in the first week of the run-in period (Day -14 to Day -8), or used the rescue medication (pinaverium bromide) in the second week of the run-in period (Day -7 to Day -1).
16. Participants with a score ≥ 60 on the Self-Rating Anxiety Scale (SAS) and/or a score ≥ 63 on the Self-Rating Depression Scale (SDS) at screening.
17. Participants with allergic diathesis or known allergy to the study drugs.
18. Participants with a history of alcohol abuse or drug abuse within the past 1 year.
19. Pregnant or lactating women; participants or their partners who plan to become pregnant during the period from signing the informed consent form to the end of follow-up, or refuse to adopt reliable non-drug contraceptive measures.
20. Participants who have enrolled in and received treatment in any other clinical trial within the past 3 months.
21. Other participants deemed unsuitable for enrollment by the investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental: Huanghou Zhixie Diwan; Huanghou Zhixie Diwan, 12 pills each time, 2 times a day, orally	Drug: Huanghou Zhixie Diwan group; The prescription consists of Magnolia Officinalis extract, Coptis Chinensis extract, Zingiber Officinale oil, and Costus Root oil
Placebo Comparator: Control: Huanghou Zhixie Diwan mimic; Huanghou Zhixie Diwan mimic, 12 pills per dose, 2 times a day, orally	Drug: Huanghou Zhixie Diwan mimic; Placebo with "no pharmaceutically active ingredients", identical to the Huanghou Zhixie Diwan in color, odor and appearance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effective rate of IBS-D (weekly response)	Proportion of subjects who met the following criteria for at least 50% of the period from randomization to the end of 4-week of treatment: patients with a reduction of at least 30% from baseline in the weekly average of the most severe abdominal pain scores over the past 24 hours; patients with a reduction of at least 50% from baseline in the number of days per week with at least one stool that has a consistency of Type 6 or 7 Bristol Stool Score compared with baseline	After 4-week treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effective rate of IBS-D (daily response)	Proportion of subjects who met the following criteria for at least 50% of the period from randomization to the end of 4-week of treatment: patients with a reduction of at least 30% from baseline in the most severe abdominal pain scores over the past 24 hours; patients whose stool type for each bowel movement is less Type 5 on the Bristol Stool Scale, or there is no bowel movement per day	After 4-week treatment
The changes in the frequency of stool Type 6 or 7 compared to baseline	Assess the changes in frequency of stool Type 6 or 7	Second and forth week of treatment
The changes in the days of stool Type 6 or 7 compared to baseline	Assess the changes in days of stool Type 6 or 7	Second and forth week of treatment
The changes in weekly average abdominal pain score compared to baseline using Numeric Rating Scale (Eleven-point scale, score range: 0-10, Lower-is-Better endpoint)	Assess the changes in weekly average abdominal pain score	Second and forth week of treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication
The changes in the frequency of abdominal pain compared to baseline	Assess the changes in the frequency of abdominal pain	Second and forth week of treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication
The changes in weekly average Urgency Numeric Rating Scale (Urgency NRS, Eleven-point scale, score range: 0-10, Lower-is-Better endpoint) compared to baseline	Assess the changes in weekly average Urgency NRS	Second and forth week of treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication
The changes in IBS Symptom Severity Score (IBS-SSS, score range: 0-500, Lower-is-Better endpoint) score compared to baseline	Assess the changes in IBS-SSS score compared to baseline	After 4-week treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication
Evaluation of Traditional Chinese Medicine Syndrome Efficacy	Assess the changes in Traditional Chinese Medicine (TCM) Syndrome score using a scale to be evaluated by a traditional Chinese medicine practitioner based on the patient's symptoms. The scale includes 2 primary symptoms and 4 secondary symptoms, and the assessment covers abdominal pain, diarrhea, bowel habits, and other related symptoms. The scale's score ranges is 0-24 and lower scores mean a better outcome. A reduction from baseline of ≥30% in the Traditional Chinese Medicine (TCM) Syndrome score is considered clinically effective, while a reduction of <30% is considered clinically ineffective.	After 2-week, 4-week treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication
The changes in Patient-Reported Outcome Instrument for Chronic Gastrointestinal Diseases (Thirty-five-item scale, score range: 0-139, Lower-is-Better endpoint) compared to baseline	Assess the changes in Patient-Reported Outcome Instrument for Chronic Gastrointestinal Diseases	After 4-week treatment, 4 weeks after discontinuing medication, 8 weeks after discontinuing medication

Collaborators and Investigators

• Sponsor: Lei Yunshang Group

Study record dates

Study Major Dates

• Study Start (Estimated): July 31, 2026
• Primary Completion (Estimated): August 31, 2027
• Study Completion (Estimated): August 31, 2027

Study Registration Dates

• First Submitted: July 16, 2026
• First Submitted That Met QC Criteria: July 20, 2026
• First Posted (Actual): July 22, 2026

Study Record Updates

• Last Update Posted (Actual): July 22, 2026
• Last Update Submitted That Met QC Criteria: July 20, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: HHZXDW-2025-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No