Population Intervention Outcomes Study/Design/Population Age years (SD) Baseline weekly frequency of spontaneous bowel movements (standard deviation) Intervention/dose/duration Control Study follow-up period in days Weight mean (standard deviation) kg Sex (%) Definition of constipation Weir 2018 Adults ≥18 yrs. Parallel-group double-blind RCTN = 58 Age range: 23 to 65 2.2 (0.8) Zyactinase capsules 2160 mg/day given as 720 mg tid Placebo capsules containing the same color isomalt given at the same frequency as an intervention 14 (i) SBM† (ii) Modified BSS§ (score 1–3) (iii) Abdominal pain (iv) Adverse events (nonreported) Not reported Not reported FC# defined by the author Kindleysides 2015 Adults ≥18 yrs. Crossover double-blind RCTN = 40 Age: 40.8 (13.2) 2.4 (0.1) Encapsulated kiwifruit extracts containing skin, flesh, and seeds, 1000 mg/day given as 500 mg bid Placebo was encapsulated magnesium stearate matched for weight, color, and size given at the same frequency as intervention 21 (i) SBM† (ii) BSS§ (iii) GSRS (iv) Adverse events Weight 68 (14.7) Female (93%) FC defined by author Ansell 2015 Adults ≥18 yrs. Crossover double-blind RCTN = 9 Age: 44 (6) Not reported Encapsulated kiwifruit extracts containing high dose Actazin 2400 mg/day given as 600 mg qid Placebo capsules containing isomalt given at the same frequency as intervention 28 (i) SBM† (ii) BSS§ (iii) frequency of SBM† with straining (iv) incomplete evacuation (v) bloating (vi) flatulence (vii) laxatives (viii) abdominal pain Weight: 67 (8) Female (89%) Rome III FC criteria Udani 2013 Adults ≥18 yrs. Parallel-group double-blind placebo-controlled RCTN = 87 Age: 39.3 (13.8) 2.1 (0.6) Kivia powder containing zyactinase 5500 mg/day given once daily in a sachet Placebo was powder containing inactive compounds in identical sachet to kivia given same frequency as intervention 28 (i) CSBM◊ (ii) BSS§ (iii) abdominal pain (iv) bloating (v) flatulence (vi) satisfaction with bowel habits (vii) use of rescue laxatives (viii) adverse events Weight: 73.5 (14.1) Female (64%) Rome III FC criteria Barbara 2018 Adults ≥18 yrs. Crossover, single-blind 3-centre RCTN = 117 Not reported 3.5 (2.2) Kiwifruit, 2 fruits/day Psyllium 7.5 grams/day 14 (i) CSBM◊ (ii) BSS§ (iii) GSRS IBS-C‡ QoL questionnaire Eady 2019 Adults ≥18 yrs. Crossover, single-blind, RCTN = 35 Age: 47 (12.9) 3.0 (1.6) Kiwifruit, 3 fruits daily Metamucil 2.5 teaspoons (5 g of fibre total) daily 45 (i) CSBM◊ (ii) BSS§ (iii) GSRS (iv) Rome III classification Weight 67.5 (14.4) Female (100%) Rome III: (i) FC (29%) (ii) IBS-c‡ (71%) Chey 2021 Adults ≥18 yrs. Parallel-group nonblinded partial RCTN = 79 Age 44.9 (16.8) 1.2 (1.5) 2 green kiwifruit daily (Actinidia deliciosa var. Hayward, fibre 6 g/day) 12 g of psyllium daily 28 (i) CSBM◊ responder rate defined as ≥1 CSBM◊ /week (ii) CSBM◊ and SBM frequency (iii) BSS (iv) frequency of straining (v) abdominal pain (vi) bloating (vii) adverse events Weight: NR Female (87%) Rome III: (i) FC (71%) (ii) IBS-C (33%)