A Double-blinded,Double-dummy Clinical Trial of Chinese Herbal Medicine (MaZiRenWan) for Functional Constipation

• the responder rate for CSBM during the treatment period [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  a clinically meaningful endpoint by combining an objective measure (number of bowel movement) with a subjective measure (feelings of patients as to completeness of defecation,Patients with a mean increase of ≧1 complete spontaneous bowel movement(CSBM)/wk compared with the baseline(wk1-2) will be defined as responders
  
  

• the responder rate for CSBM during the follow-up period [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  Participants with a mean increase of complete spontaneous bowel movement (CSBM)>=1 movement per week compared with the last 14 days of the run-in period were defined as responders
  
  
• Individual assessment of constipation and related symptoms [ Time Frame: 18 weeks ] [ Designated as safety issue: No ]
  severity of constipation, sensation of straining, incomplete evacuation, bloating, abdominal pain / cramping, nausea, and passing of gas) was recorded using a 7-point ordinal scale (0 = not at all and 6 = very severe
  
  
• the changes of colonic transit time [ Time Frame: 18 weeks ] [ Designated as safety issue: No ]
  It is estimated by using a commercially available radio-opaque Sitzmarks capsule (Konsyl Pharmaceuticals, US). Each gelatine capsule contained 24 barium sulphate embedded polyvinyl chloride markers measuring 1mmx4.5mm. Plain radiographs of the abdomen will be obtained after the swallow of capsule for five days (120 hours) before and after 8 weeks treatment period.
  
  
• Global symptom assessment [ Time Frame: 18 weeks ] [ Designated as safety issue: No ]
  Participants were asked to rate their impression of change in constipation by comparing with their baseline (Wk2) at the visits during the treatment (Wk6), end of treatment (Wk10) and end of follow-up (Wk18) with scores from 0 to 6 represented markedly worse or better respectively. The response categories were collapsed to simply "improved" for score 4 to 6, "same" for score 3 or "worse" for score 0 to 2.
  
  
• Success of blinding [ Time Frame: 18 weeks ] [ Designated as safety issue: No ]
  the success of blinding is evaluated for both investigator and patients as to whether CHM, WM or placebo had been taken
  
  
• safety profiles [ Time Frame: 18 weeks ] [ Designated as safety issue: Yes ]
  Assessed by determining the important adverse events reported in the participants ' diaries, follow-up interviews,and clinical laboratory evaluationse.g., liver and renal function.
  
  
• changes of the parametres measured by anorectal manometry, [ Time Frame: 18 weeks ] [ Designated as safety issue: No ]
  Water perfused system with anorectal catheter with 4 side holes was used to record length of anal canal or high-pressure zone, resting pressure of anal canal, and rectoanal inhibitory reflex
  
  

Functional constipation (FC) is a common clinical complaint. Despite the effectiveness of MaZiRenWan (MZRW) for alleviating FC symptoms has been proofed in the previous study.Given the results of the dose determination study and placebo-controlled study of MZRW, we hypothesize that MZRW is more useful than senna (senokot), a commonly used WM drug for constipation, for FC patients in excessive TCM syndrome.This is a prospective, double-blind, double dummy, randomized, controlled trial. After a 2-week run-in, eligible FC patients (Rome III) in excessive TCM syndrome will randomly be assigned to CHM arm (MZRW and WM placebo), WM arm (senna and CHM placebo) or placebo arm (CHM placebo and WM placebo). Patients will undergo an 8-week treatment and an 8-week follow-up.