Does kiwi fruit help with constipation?

Yes, modestly, and as the whole fruit. In a crossover trial in three countries, adults who ate 2 green kiwifruits a day for 4 weeks gained 1.53 complete bowel movements a week if they had functional constipation and 1.73 if they had IBS with constipation. One pooled analysis put kiwifruit slightly ahead of psyllium, a fiber supplement, at 0.36 more bowel movements a week, and another found no difference in how many people responded. Kiwifruit in capsules did nothing measurable.

Unsettled. Every trial of the whole fruit compared it with psyllium, prunes or the person's own starting point. We found no trial against placebo. So kiwifruit did about as well as a fiber supplement, and nobody has measured exactly how much of the gain is the fruit itself.

What the trials found

The whole fruit

The largest trial of whole kiwifruit is the one in the chart, 184 people in three countries, each eating 2 green kiwifruits a day for 4 weeks and psyllium for another 4. The company that sells the fruit funded it, and the authors say so. A 2024 meta-analysis of 23 studies with 1714 participants, 7 of them on kiwifruit, found kiwifruit gave 0.36 more bowel movements a week than psyllium (95% CI 0.24 to 0.48, 192 people). Prunes did no better than psyllium. A third of a bowel movement a week is a small number, and its authors call the evidence base scarce.

The British Dietetic Association pooled the same head-to-head trials for its 2025 guideline. Kiwifruit did not make more people respond than psyllium did, a risk ratio of 1.32 (95% CI 0.91 to 1.92) across 2 trials of 184 people, and the guideline rates that evidence low. Stools were no softer either, at 0.32 points more on the Bristol stool scale (95% CI -0.12 to 0.76) across 3 trials of 192 people.

A US trial of 79 adults with chronic constipation, only partly randomized, gave 2 kiwifruits a day, 3.5 oz (100 g) of prunes or 12 g of psyllium for 4 weeks. The share of people who responded was similar across the three. Older and smaller studies point the same way and cannot carry much weight. In 33 Chinese adults with constipation, kiwifruit twice a day for 4 weeks took complete bowel movements from 2.2 to 4.4 a week, with no comparison group. In 38 healthy adults over 60, one kiwifruit per 30 kg of body weight a day for 3 weeks gave more frequent, bulkier and softer stools than their usual diet, in a trial without randomization.

For IBS with constipation, a 2026 network meta-analysis of 12 randomized trials found natural fruits eased abdominal pain more than dietary fiber, a mean difference of -0.23 (95% credible interval -0.45 to -0.01), on evidence it rated high certainty. Kiwis and figs were grouped together there, so the result is for fruit as a class.

Capsules and extracts

Myth. Kiwifruit in a capsule is not the fruit. A 2023 meta-analysis of 3 randomized trials found kiwifruit supplements changed stool frequency by 0.24 bowel movements a week (95% CI -0.32 to 0.80) and stool form by -0.11 Bristol points (95% CI -0.31 to 0.09), neither significant. In a placebo-controlled crossover trial that 32 constipated adults completed, 1 g a day of freeze-dried green kiwifruit extract for 3 weeks did no better than placebo.

Who should be careful

Not for everyone. Kiwi allergy is the real caution. In a Spanish series of people sensitized to kiwi who were given a blinded food challenge, 46% had symptoms beyond the mouth, and every patient without a pollen allergy did. That was one center, and it gives no rate for the general population. 28% of the same patients were sensitized to latex.

Cooking does not make the fruit safe for everyone who reacts to it. In a study of 20 children allergic to fresh kiwifruit, one reacted on a blinded challenge with steamed kiwifruit, while none reacted to an industrially homogenized preparation. If you or your child react to kiwi, this page is not a reason to try it.

For people without the allergy, kiwifruit was the gentlest option tested. In the US trial above, side effects were least common with kiwifruit and most common with psyllium, and fewer people were dissatisfied with kiwifruit at the end (P = 0.02). We found no trial in children or in pregnancy.

What expert bodies say

The British Dietetic Association's 2025 guideline says 2 to 3 kiwifruit a day for at least 4 weeks may be recommended for constipation, and that kiwifruit without the skin may be recommended. It suggests kiwifruit may be preferred over psyllium for people who get bloating, abdominal pain or wind from psyllium.

A 2021 systematic review of over-the-counter treatments graded fruit-based laxatives, kiwi, mango, prunes and figs, as moderate evidence. Polyethylene glycol and senna had the stronger grade. So kiwifruit is a reasonable food to try for a month. If constipation is long-standing or comes with new symptoms, it is worth raising with a doctor rather than relying on fruit.

More on the fruit itself, including what is in it, is on the kiwi fruit page.

How we searched

What would change this answer

• A trial of the whole fruit against a placebo or a neutral food, which would say how much of the gain belongs to the kiwifruit. We found none.
• Trials in children and in pregnancy, two groups where constipation is common and we found no data.
• A trial of the whole fruit run without funding from the kiwifruit industry, since the largest trial so far was funded by a company that sells the fruit.
• A registered trial now running. ClinicalTrials.gov had none for kiwifruit and constipation when we searched.

Sources

1. ev-kwc-01 · Randomized controlled trial(s) · international multicenter randomized AB/BA crossover trial, kiwifruit vs psyllium 7.5 g/day, 4 weeks each with 4-week washout · n = 184
   The primary outcome of an increase of ≥ 1.5 CSBM per week was achieved in the FC (mean 1.53, P < 0.0001), IBS-C (mean 1.73, P = 0.0003), and combined FC + IBS-C (mean 1.69, P < 0.0001) groups after the kiwifruit intervention. After the psyllium intervention, the primary outcome was observed only in the IBS-C (mean 1.87, P = 0.0051) group (Table 2). In the combined FC and IBS-C group, the effect of 2 green kiwifruits per day was significantly greater than the effect of psyllium (P = 0.038) (Figure 4).
   
   Who: healthy controls (n = 63), patients with functional constipation (FC, n = 60), and patients with constipation-predominant irritable bowel syndrome (IBS-C, n = 61)
   Effect: CSBM per week +1.53 (FC, P < 0.0001), +1.73 (IBS-C, P = 0.0003), +1.69 combined; kiwifruit greater than psyllium in combined group (P = 0.038)
   Certainty: The largest RCT of a whole fruit; funded by Zespri (a kiwifruit producer), which the authors disclose. Comparison with psyllium, no placebo.
   Am J Gastroenterol, 2023, Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort · checked 2026-10-07 · we read the fulltext
2. ev-kwc-02 · Meta-analysis or systematic review · guideline built on systematic review and meta-analysis of RCTs with GRADE · n = 2 RCTs, 184 people
   Two RCTs, including 184 people with chronic constipation, assessed the effect of kiwifruit in symptomatic response to treatment, measured as a binary outcome [14]. Overall, kiwifruits had no greater impact on response to treatment compared to psyllium supplements (RR: 1.32, 95% CI: 0.91, 1.92).
   
   Who: people with chronic constipation
   Effect: response to treatment RR 1.32 (95% CI 0.91 to 1.92) vs psyllium; level of evidence low
   Certainty: Psyllium is an active control with demonstrated action; "not worse than psyllium" is not the same as "like placebo".
   J Hum Nutr Diet, 2025 · checked 2026-10-07 · we read the fulltext
3. ev-kwc-03 · Meta-analysis or systematic review · guideline built on systematic review and meta-analysis of RCTs with GRADE · n = 3 RCTs, 192 people
   Kiwifruits had no significantly greater impact on stool consistency when compared to psyllium supplements (MD: +0.32 points on the Bristol Stool Form Scale, 95% CI: −0.12, 0.76 points).
   
   Who: people with chronic constipation
   Effect: stool consistency MD +0.32 Bristol points (95% CI -0.12 to 0.76) vs psyllium
   J Hum Nutr Diet, 2025 · checked 2026-10-07 · we read the fulltext
4. ev-kwc-04 · Position of an expert body · professional society guideline, GRADE and Delphi · n = —
   Consumption of 2–3 kiwifruit daily for at least 4 weeks may be recommended in constipation (evidence‐based recommendation).Kiwifruit without skin may be recommended for constipation (evidence‐based recommendation).
   
   Who: adults with chronic constipation
   Effect: 2-3 kiwifruit daily for >=4 weeks; kiwifruit without skin may be recommended
   Certainty: "Good practice" advice based on an RCT; about the peel it is expert opinion.
   J Hum Nutr Diet, 2025 · checked 2026-10-07 · we read the fulltext
5. ev-kwc-05 · Position of an expert body · professional society guideline, GRADE and Delphi · n = —
   Kiwifruit may be a preferred option over psyllium in people with constipation who experience side effects such as bloating, abdominal pain and flatulence (evidence‐based recommendation).
   
   Who: adults with chronic constipation
   Effect: kiwifruit as an option when psyllium causes bloating, abdominal pain or flatulence
   J Hum Nutr Diet, 2025 · checked 2026-10-07 · we read the fulltext
6. ev-kwc-06 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 8 RCTs, 787 participants overall; 3 kiwifruit RCTs
   Kiwifruit supplements did not impact stool frequency (MD 0.24 bowel movements/week [-0.32, 0.80]; p = 0.40) or consistency (MD -0.11 Bristol points [-0.31, 0.09], p = 0.29).
   
   Who: adults with chronic constipation in RCTs of food, vitamin or mineral supplements
   Effect: stool frequency MD 0.24 BM/week (95% CI -0.32 to 0.80); consistency MD -0.11 Bristol points (95% CI -0.31 to 0.09)
   Certainty: Whole fruits are excluded by design; the conclusion is only about capsules and sachets.
   Neurogastroenterol Motil, 2023 · checked 2026-10-07 · we read the abstract
7. ev-kwc-07 · Randomized controlled trial(s) · double blind, randomized, placebo controlled crossover trial · n = 40 entered, 32 completed
   CONCLUSIONS: This trial showed that improvement in bowel function or comfort was not achieved through supplementation with 1 g/day freeze dried kiwifruit extract.
   
   Who: adults with confirmed constipation
   Effect: no difference in total bowel movements over 3 weeks or weekly means vs placebo (p>0.05)
   Asia Pac J Clin Nutr, 2015 · checked 2026-10-07 · we read the abstract
8. ev-kwc-08 · Observational data · partially randomized comparative effectiveness trial · n = 79 partially randomized, 75 analyzed
   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).
   
   Who: Adults with CC at a US medical center
   Effect: similar proportions of CSBM responders across kiwifruit, prunes 100 g/d and psyllium 12 g/d; adverse events least common and dissatisfaction lowest with kiwifruit (P = 0.02)
   Certainty: A "partially randomized" study, hence C, not B. Small groups (29/24/22).
   Am J Gastroenterol, 2021, Exploratory Comparative Effectiveness Trial of Green Kiwifruit, Psyllium, or Prunes in US Patients With Chronic Constipation · checked 2026-10-07 · we read the abstract
9. ev-kwc-09 · Observational data · uncontrolled before-after trial against a run-in baseline · n = 53
   Responder rate was 54.5% in the constipated group. The mean CSBM increased after treatment (2.2 +/- 2.6 vs 4.4 +/- 4.6, P = 0.013).
   
   Who: 33 constipated patients and 20 healthy volunteers
   Effect: responder rate 54.5%; CSBM 2.2 +/- 2.6 vs 4.4 +/- 4.6 per week (P = 0.013); colonic transit improved (P = 0.003)
   Certainty: No control group, comparison with baseline.
   World J Gastroenterol, 2007 · checked 2026-10-07 · we read the abstract
10. ev-kwc-10 · Observational data · non-randomized controlled crossover trial · n = 38
    Kiwifruit significantly enhanced all tested measures of laxation in these adults. The regular use of kiwifruit appeared to lead to a bulkier and softer stool, as well as more frequent stool production.
    
    Who: Thirty-eight healthy adults of age > 60 years
    Effect: all tested measures of laxation enhanced; no effect sizes in abstract
    Certainty: No randomization in the abstract and no effect sizes; healthy older people, not people with constipation.
    Asia Pac J Clin Nutr, 2002 · checked 2026-10-07 · we read the abstract
11. ev-kwc-11 · Meta-analysis or systematic review · systematic review and network meta-analysis of randomized controlled trials · n = 12 RCTs
    Network meta-analysis results demonstrated natural fruits were more effective than dietary fiber in alleviating abdominal pain (MD, -0.23 [95% credible interval (CrI), -0.45 to -0.01]; high-certainty evidence, category 1).
    
    Who: patients with irritable bowel syndrome with constipation in randomized controlled trials
    Effect: fruits vs dietary fiber abdominal pain MD -0.23 (95% CrI -0.45 to -0.01), high-certainty evidence
    Certainty: Kiwi and fig combined in "natural fruits"; the abstract gives no separate assessment for kiwi.
    Nutr Rev, 2026 · checked 2026-10-07 · we read the abstract
12. ev-kwc-12 · Observational data · double-blind placebo-controlled food challenge study, non-randomized · n = 43 evaluated, 33 challenged, 23 positive
    Forty-six percent of patients experienced systemic symptoms, and this happened with higher frequency in patients not allergic to pollen (100%). Twenty-eight percent of the patients were sensitized to latex.
    
    Who: Forty-three patients with allergy symptoms who were sensitized to kiwi
    Effect: 46% systemic symptoms; 100% systemic among those not allergic to pollen; 28% sensitized to latex; 4 had prior severe anaphylaxis
    Certainty: Series from one center (Spain, no birch); does not give allergy frequency in the population. Nonrandomized challenge = C.
    J Allergy Clin Immunol, 2004 · checked 2026-10-07 · we read the abstract
13. ev-kwc-13 · Meta-analysis or systematic review · systematic review of randomized controlled trials, USPSTF-based grading · n = 41 studies
    There was good evidence (grade A recommendation) for the use of the osmotic laxative polyethylene glycol (PEG) and the stimulant senna; moderate evidence (grade B) for psyllium, SupraFiber, magnesium salts, stimulants (bisacodyl and sodium picosulfate), fruit-based laxatives (kiwi, mango, prunes, and ficus), and yogurt with galacto-oligosaccharide/prunes/linseed oil; and insufficient evidence (grade I) for polydextrose, inulin, and fructo-oligosaccharide.
    
    Who: randomized controlled trials of >=4-week duration of OTC preparations for chronic constipation, 2004 to 2020
    Effect: grade B (moderate evidence) for fruit-based laxatives; grade A for PEG and senna
    Am J Gastroenterol, 2021 · checked 2026-10-07 · we read the abstract
14. kwi-r2-01 · Meta-analysis or systematic review · systematic review and meta-analysis of intervention trials on foods, drinks and diets in chronic constipation, databases searched to 12 July 2023, randomized trials synthesized with random effects as risk ratios, mean differences and standardized mean differences, risk of bias by Cochrane 2.0 and JBI · n = 1714
    Fruits resulted in higher stool frequency than psyllium (MD: +0.36 bowel movements [BM]/week, [0.25-0.48], n = 232), kiwifruits in particular (MD: +0.36 BM/week, [0.24-0.48], n = 192); there was no difference for prunes compared with psyllium.
    
    Who: 23 studies with 1 714 participants, of which 7 were kiwifruit trials
    Effect: fruits gave higher stool frequency than psyllium (+0.36 bowel movements a week, 95% CI 0.25 to 0.48, n = 232) and kiwifruit in particular (+0.36, 95% CI 0.24 to 0.48, n = 192), with no difference for prunes against psyllium; rye bread beat white bread (+0.43, 0.03 to 0.83); high-mineral water beat low-mineral water for treatment response (RR 1.47, 1.20 to 1.81)
    Certainty: a third of a bowel movement a week is a small number honestly reported, and the comparator is psyllium rather than nothing, so this says kiwifruit is at least as good as a fiber supplement rather than that it is powerful. The authors end by calling the evidence base scarce. The kiwifruit trials are also the ones most often funded by the industry that sells them
    Aliment Pharmacol Ther, 2024 · checked 2026-09-22 · we read the abstract
15. kwi-r2-07 · Randomized controlled trial(s) · prospective trial with double-blind placebo-controlled food challenges to steam-cooked kiwifruit (212 °F / 100 °C for 5 minutes) and to an industrially homogenized preparation, with skin prick tests to commercial allergen and raw fruit, a confirmatory challenge with 0.88 oz (25 g) of fresh kiwifruit, and specific IgE identified by immunoblotting · n = 20
    There was no clinical reactivity following challenge with homogenised kiwifruit but one child reacted to cooked kiwifruit challenge.
    
    Who: 20 children with a history of immediate allergic reactions to fresh kiwifruit, median age 9.4 years
    Effect: fresh kiwifruit gave positive skin prick wheals in all 20 and reactions on challenge in 19; the commercial skin prick test was positive in five and steam-cooked kiwifruit in five, the homogenized preparation in none; no child reacted clinically to the homogenized preparation, one reacted to the cooked challenge; major allergens identified were Act c 1 and Act c 2
    Certainty: twenty children in 2004, and the homogenized product was one specific industrial preparation rather than a category. The distinction is the useful part and it cuts against the common shorthand that cooking destroys food allergens: five minutes of steam left enough allergen for one child to react, while industrial processing did not. Nobody should test this at home on the strength of twenty children
    Pediatr Allergy Immunol, 2004 · checked 2026-09-22 · we read the abstract