Glucomannan for Childhood Functional Constipation.


The purpose of this study is to determine whether administration of glucomannan (dietary fiber) is effective in treating functional constipation in children.

Full Title of Study: “Glucomannan in Treating Childhood Functional Constipation: a Randomized, Double-blind, Placebo-controlled Trial.”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
  • Study Primary Completion Date: June 2010

Detailed Description

Constipation is a common condition in children. In many patients symptoms persist to adulthood and decrease quality of life. The standard treatment, mostly osmotic laxatives such as lactulose or polyethyleneglycols, are often ineffective and may cause adverse events. Therefore, alternative treatment measures are being searched for. Glucomannan, a water-soluble fiber polysaccharide from the tubers of the Japanese Konjac plant, has been reported to be effective in constipated children. To date, 2 randomized trials were performed.1,2 One evaluated the effect as glucomannan as an adjunct to standard treatment.1 Another was conducted in neurologically impaired children, who constitute a specific population that cannot be compared to patients with functional constipation.2 In both trials, the number of patients was relatively small. Well-powered, randomized controlled study is required to evaluate clinical effectiveness of glucomannan as a sole treatment in childhood functional constipation.


  • Dietary Supplement: Glucomannan
    • 1.26 g per sachet; 2 sachets per day for 4 weeks.
  • Dietary Supplement: maltodextrin
    • prepared in sachets (1.3g); 2 sachets per day for 4 weeks

Arms, Groups and Cohorts

  • Experimental: Glucomannan
    • glucomannan preparation in sachets: 1 saschet of 1.26g 2 times per day (daily dosage 2,52g); duration of intervention: 4 weeks
  • Placebo Comparator: Placebo
    • maltodextrin prepared in sachets (1,3 g per sachet); 2 sachets per day; duration of intervention: 4 weeks

Clinical Trial Outcome Measures

Primary Measures

  • treatment success
    • Time Frame: 1 week
    • paasing at least 3 stools per week with no episodes of soiling

Secondary Measures

  • stool frequency
    • Time Frame: 1 week
    • number of stools passes per week
  • soiling
    • Time Frame: 1 weeks
    • number of episodes of soiling per week
  • hard stools or painful defecations
    • Time Frame: 1 week
    • number of hard stools passed or painful defecations per week
  • abdominal pain
    • Time Frame: 1 week
    • number of episodes of abdominal pain per week
  • need for interventional laxative
    • Time Frame: 1 week
    • need for rescue treatment (osmotic laxative: lactulose 1 ml of syrup per 1 kg of body weight) when no stool passed for 3 consecutive days)
  • flatulence
    • Time Frame: 1 week
    • number of episodes of flatulence per 1 week
  • adverse events
    • Time Frame: 4 weeks
    • any adverse events (mild or seriuos) reported by parents during the study period(pain, infections, hospitalizations, accidents or any other event related or not related to study intervention)

Participating in This Clinical Trial

Inclusion Criteria

  • functional constipation diagnosed according to Rome Criteria III (duration of symptoms for at least 2 months prior to study inclusion) – age 3 to 16 years – informed consent from parents and/or child Exclusion Criteria:

  • organic cause of defecation disorders (Hirschsprung's disease, spinal anomalies or anorectal pathology; history of gastro-intestinal surgery) – mental retardation – metabolic disease (e.g. hypothyroidism) – irritable bowel syndrome – intake of medications influencing gastrointestinal motility

Gender Eligibility: All

Minimum Age: 3 Years

Maximum Age: 16 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Medical University of Warsaw
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Hania Szajewska, Professor, Study Director, The Medical University of Warsaw


Hyman PE, Milla PJ, Benninga MA, Davidson GP, Fleisher DF, Taminiau J. Childhood functional gastrointestinal disorders: neonate/toddler. Gastroenterology. 2006 Apr;130(5):1519-26. doi: 10.1053/j.gastro.2005.11.065.

Citations Reporting on Results

Belsey J, Greenfield S, Candy D, Geraint M. Systematic review: impact of constipation on quality of life in adults and children. Aliment Pharmacol Ther. 2010 May;31(9):938-49. doi: 10.1111/j.1365-2036.2010.04273.x. Epub 2010 Feb 20.

Pijpers MA, Tabbers MM, Benninga MA, Berger MY. Currently recommended treatments of childhood constipation are not evidence based: a systematic literature review on the effect of laxative treatment and dietary measures. Arch Dis Child. 2009 Feb;94(2):117-31. doi: 10.1136/adc.2007.127233. Epub 2008 Aug 19. Erratum In: Arch Dis Child. 2009 Aug;94(8):649.

Loening-Baucke V, Miele E, Staiano A. Fiber (glucomannan) is beneficial in the treatment of childhood constipation. Pediatrics. 2004 Mar;113(3 Pt 1):e259-64. doi: 10.1542/peds.113.3.e259.

Staiano A, Simeone D, Del Giudice E, Miele E, Tozzi A, Toraldo C. Effect of the dietary fiber glucomannan on chronic constipation in neurologically impaired children. J Pediatr. 2000 Jan;136(1):41-5. doi: 10.1016/s0022-3476(00)90047-7.

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