Kiwis could help manage chronic constipation

Kiwifruits, rye bread and high mineral-content water could all help alleviate chronic constipation.

That’s according to the first ever evidence-based dietary guidelines for adults with chronic constipation, led by researchers at King’s College London.

The new guidelines also show that taking psyllium fibre supplements, certain probiotic strains and magnesium oxide supplements can help to improve constipation.

In contrast, other widely recommended approaches, including generic “high-fibre diets,” and senna supplements (a type of laxative) were found to lack strong evidence of effectiveness.

The guidelines, jointly published in two international journals, the Journal of Human Nutrition & Dietetics and Neurogastroenterology & Motility, are endorsed by the British Dietetic Association (BDA) and aim to transform the way this common condition is managed by doctors, nurses and dietitians in clinical practice. The guidelines could also allow better self-management of symptoms, particularly through foods and drinks.

Constipation is a long-term condition that significantly impacts quality of life and places a considerable financial burden on both patients and healthcare systems. Until now, clinical guidelines have offered only limited and sometimes outdated dietary recommendations, typically increasing dietary fibre and fluid intake.

Unlike previous guidelines, the new recommendations are based on numerous rigorous systematic reviews and meta-analyses, and applying the GRADE framework to assess the quality of the evidence. A multidisciplinary panel of experts, including dietitians, and a nutritionist, gastroenterologist, gut physiologist, and GP, reviewed over 75 clinical trials to create 59 recommendation statements and identify 12 research priorities.

Dr Eirini Dimidi, Reader in Nutritional Sciences at King’s College London and lead author, said: “Chronic constipation can have a huge impact on someone’s day-to-day life. For the first time, we’ve provided direction on what dietary approaches could genuinely help, and which diet advice lacks evidence. Being able to improve this condition through dietary changes would allow people to self-manage their symptoms more and, hopefully, improve their quality of life.”

The recommendations also focus on constipation outcomes such as stool frequency, stool consistency, straining and quality of life, making them more practical for personalised care based on the specific symptoms each individual experiences. A clinician-friendly tool has also been developed to support the adoption of these guidelines in everyday practice across the world.

The evidence review revealed that, while some foods and supplements are effective, the overall quality of existing studies is low. Most trials focused narrowly on single interventions rather than whole diet approaches, highlighting the urgent need for better nutrition research in constipation management.

Dr Dimidi added: “Eating a high fibre diet offers many benefits to overall health and has been a go-to recommendation for constipation. However, our guidelines found that there simply isn’t enough evidence to suggest it actually works in constipation specifically. Instead, our research reveals some new dietary strategies that could indeed help patients. At the same time, we urgently need more high-quality trials to strengthen the evidence on what works and what doesn’t.”

Professor Kevin Whelan, senior author and Professor of Dietetics at King’s College London, said: “This new guidance marks a promising step towards empowering health professionals and their patients to manage constipation through diet. This means that from now on that people suffering from constipation across the world can now receive up-to-date advice based upon the best available evidence in order to improve their symptoms and wellbeing. With continued research, it holds real potential to drive lasting improvements in quality of life.”