Traditional Chinese Medicine for Treatment of Irritable Bowel Syndrome

This will be a 10 week randomized, double blind, parallel group, single center study on patients who fulfil ROME III criteria for IBS-Constipation predominant subtype (IBS-C) and TCM syndrome of Liver Qi stagnation.The study will consist of a two week baseline run-in period without medication, an 8 week randomized double blind treatment period with either placebo or CHM (twice daily), followed by an optional further 12 week withdrawal period with no medication.

Patients who fulfill ROME III criteria for IBS-C will be assessed by a designated qualified traditional Chinese physician. Patients who fulfill TCM syndrome diagnosis of Liver Qi stagnation will be eligible participate in the study.

Each patient's TCM syndrome differentiation and modifications as well as corresponding prescription will be assessed by a second TCM physician to evaluate for reproducibility of TCM diagnosis.

The TCM physician will prescribe the appropriate treatment formula based on TCM principles (see intervention section):

Placebo will constitute granules with 10% active core ingredients. This choice of placebo has been validated in a thesis which showed that the decoction compounded this way was indistinguishable by an intelligent sensory machine in taste, smell and appearance compared to the active treatment formula while not possessing any significant therapeutic effect in animal models

The herbal formulas will be provided in the form of an identical packet of granules for each patient. The patient will be dissolved the granules in water before taking. The patient needs to take one packet of the assigned formulation per time and 2 times a day for the next 8 weeks. The formula will be fixed throughout the 8 week treatment period.

At screening, patients will provide blood for routine testing (FBC,UECr,LFT,PT,APTT and ECG). Patients' medications will be screened and patients instructed to discontinue any medications drugs which may alter GI motility or microbiota (eg: opioids, prokinetics and antibiotics). except bisacodyl).Patients are allowed to take bisacodyl when abdominal pain or discomfort ≥7 on an 11-point numeric rating scale. Data from patient's symptoms during the 2 run-in weeks will be used as the baseline. The subjects will visit the study site at the start and end of the baseline screening period (days 0 and 14), week 4 of during the treatment, end of treatment (week 8), and at the end on the 12 week follow up period. During all these visits, they will be evaluated by the primary investigators and our TCM collaborators. At the end of 4 weeks of treatment, patient's TCM syndrome will be reassessed by the TCM physician to evaluate for mid treatment changes. The diagnosis will performed by a second TCM physician to check for reproducibility. In addition, the patients will be contacted by phone or email weekly to monitor treatment compliance and symptoms. Where necessary, the use of rescue medication bisacodyl 5 mg tablets will be allowed and the quantity of usage will be recorded weekly.

In order to assess mechanisms associated with the patients symptom changes, two approaches will be adopted. First, whole and regional GI transit times will be assessed using the wireless motility capsule. Second, CHM and/or placebo associated changes to the resident bacterial populations, or microbiome, in GI will be assessed by deep sequencing the hypervariable regions of the 16s gene. Patients will be advised not to change their usual diet and exercise level during the trial as this has been shown to alter gut microbiome and motility. The patients' baseline and end of treatment diet will be assessed on weeks 2 and 10 respectively by means of a 3 days food diary (2 week day and 1 weekend day) with verbal and written instructions explaining that they should add to their diary every time they eat or drink, describing the food as accurately as possible and giving estimates of amounts. The completed food records would be evaluated and analysed by the dietician. The patients' exercise levels will be assessed with a validated questionnaire, International physical activity questionnaire(IPAQ) Efficacy assessments and end points

The following symptoms will be recorded: worst abdominal pain (an 11-point numeric rating scale), abdominal discomfort (an 11-point numeric rating scale), abdominal cramping (an 11-point numeric rating scale), abdominal fullness (an 11-point numeric rating scale), abdominal bloating (an 11-point numeric rating scale), IBS Symptom severity score (IBS-SSS), Quality of life questionnaire EQ-5D, Hospital anxiety depression scale, 15 item Somatic Symptom Severity Scale, the number of BMs, quantity of rescue medication used (bisacodyl 5 mg tablets), TCM IBS symptom score Economic Costs of Functional Gastrointestinal Disorders, IPAQ_English_self-admin, IBSMode Questionnaire, Patient's Diary, Food Diary and .TCM Liver Qi Stagnation.

Each BM was assessed for: sensation of complete bowel emptying (yes/no), stool consistency (7-point Bristol Stool Chart), severity of straining (5-point ordinal scale).