Exploratory Comparative Effectiveness Trial of Green Kiwifruit, Psyllium, or Prunes in US Patients With Chronic Constipation

Am J Gastroenterol. 2021 Jun 1;116(6):1304-1312. doi: 10.14309/ajg.0000000000001149.


Introduction: Psyllium and prunes are proven treatments for chronic constipation (CC). Asian studies suggest that kiwifruit may also benefit CC symptoms. We report a partially randomized, comparative effectiveness trial evaluating kiwifruit, psyllium, and prunes in US patients with CC.

Methods: Adults with CC at a US medical center were randomized to 3 natural treatments. Eligible patients had ≤3 complete spontaneous bowel movements (CSBMs) per week and were partially randomized to green kiwifruit (2/d), prunes (100 g/d), or psyllium (12 g/d) for 4 weeks. The primary endpoint was the proportion of patients in each group reporting an increase of ≥1 CSBM per week compared with baseline for at least 2 of 4 treatment weeks. Key secondary outcomes included stool frequency, stool consistency, and straining assessed daily. Treatment satisfaction and adverse events (AEs) were also measured. Standard statistical methods were used, and a P < 0.05 was considered significant.

Results: Seventy-nine patients with CC (mean age = 42.7 years, 87% female, and 77% white) were partially randomized. Complete data were available for 75 patients (kiwifruit 29, prunes 24, and psyllium 22). For the primary endpoint, proportions of CSBM responders were similar for the treatments. For secondary outcomes comparing treatment weeks 3 and 4 to baseline, there was a significant increase in weekly CSBM rate with all 3 treatments (P ≤ 0.003); stool consistency significantly improved with kiwifruit (P = 0.01) and prunes (P = 0.049); and straining significantly improved with kiwifruit (P = 0.003), prunes (P < 0.001), and psyllium (P = 0.04). Patients randomized to the kiwifruit group reported significant improvement in bloating scores (P = 0.02). AEs were most common with psyllium and least common with kiwifruit. At the end of treatment, a smaller proportion of patients were dissatisfied with kiwifruit compared with prunes or psyllium (P = 0.02).

Discussion: Kiwifruit, prunes, and psyllium improve constipation symptoms in patients with CC. Kiwifruit was associated with the lowest rate of AEs and dissatisfaction with therapy.

Trial registration: ClinicalTrials.gov NCT00356952 NCT03569527.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinidia
  • Adult
  • Chronic Disease
  • Comparative Effectiveness Research
  • Constipation / diet therapy*
  • Female
  • Fruit*
  • Humans
  • Male
  • Prunus
  • Psyllium / therapeutic use*


  • Psyllium

Associated data

  • ClinicalTrials.gov/NCT00356952
  • ClinicalTrials.gov/NCT03569527