Chronic constipation affects roughly one in ten people worldwide. News emerging from recent research is that simple, evidence-based dietary changes may offer meaningful relief.
The first comprehensive dietary guidelines
Until now, clinical guidelines for constipation have been vague on the specifics of diet, typically limited to "eat more fibre and drink more water." In 2025, the British Dietetic Association published the first comprehensive evidence-based dietary guidelines for managing chronic constipation in adults, drawing on four systematic reviews and meta-analyses encompassing 75 randomised controlled trials.(1) Their findings move the conversation beyond generic fibre advice.
Among fibre supplements, psyllium husk emerged as the favourite, earning a strong recommendation for increasing both stool frequency and improving stool consistency. Other fibre types were less convincing: polydextrose, galacto-oligosaccharides, and mixtures of inulin with other fibres showed no significant benefit for constipation outcomes.
Magnesium oxide supplements also received a strong recommendation, with evidence showing they increase stool frequency, soften stool consistency, and reduce symptoms such as straining and bloating.
For those interested in food-based approaches, kiwifruit earned specific mention as an effective option for improving constipation symptoms, with the guidelines noting it may reduce straining, abdominal pain, and the sensation of incomplete evacuation.
Why kiwifruit deserves a spot on your shopping list
A 2022 randomised clinical trial from the University of Otago investigated whether a standard, achievable serving of two gold kiwifruitper day could match the effects of fibre-matched psyllium for constipation management.(2) The results were compelling. Over a four-week intervention period, both kiwifruit and psyllium significantly improved constipation symptom scores and increased the number of complete spontaneous bowel movements per week.
Where kiwifruit pulled ahead was in ease of defaecation: participants eating two gold kiwifruit daily experienced significantly less straining than those taking psyllium. Kiwifruit also came with notably fewer adverse events, with participants on psyllium more likely to report side effects such as bloating.
This matters because long-term adherence to any constipation treatment depends heavily on tolerability. A whole food that can be sliced into breakfast or eaten as an afternoon snack is, for many people, a more sustainable intervention than a daily supplement.
Chia seeds: an emerging contender
The latest research to enter the field is a 2025 randomised prospective trial examining chia seeds as a treatment for chronic constipation, the first clinical trial to compare them head-to-head with psyllium and polyethyleneglycol (PEG), a commonly prescribed osmotic laxative.
Adults meeting Rome IV criteria for symptomatic constipation were randomised to chia seeds (2 tablespoons/day), psyllium (12 g/day), or PEG (17g/day) for four weeks.(3) Chia seeds significantly increased the number of complete spontaneous bowel movements and improved bloating and straining scores. Notably, psyllium in this trial did not significantly alter bowel movement frequency, though it did improve stool consistency and bloating.
The researchers concluded that chia seeds represent a promising, well-tolerated, food-based option that is low in sugar, high in protein, and may appeal to patients seeking natural alternatives to pharmaceutical laxatives.
What does this mean in practice?
The collective message from this body of research is encouraging: dietary interventions for chronic constipation are increasingly supported by evidence. Psyllium remains a reliable option, but whole foods, particularly kiwi fruit and potentially chia seeds, offer genuine alternatives that may suit your lifestyle, palate, and gut.
As always, persistent changes in bowel habits warrant a conversation with your healthcare provider to rule out underlying causes.
