A new set of evidence-based dietary guidelines from the British Dietetic Association (BDA) highlights that kiwifruit, rye bread, and high mineral-content water may be among the most effective natural remedies for chronic constipation.

The recommendations, based on an analysis of 75 clinical trials, mark the first time the BDA has provided comprehensive, evidence-backed dietary strategies for managing constipation. The findings were co-published in the Journal of Human Nutrition & Dietetics and Neurogastroenterology & Motility.

Chronic Constipation: A Common Yet Often Overlooked Condition

Chronic constipation affects up to 20% of adults in the United States, causing discomfort, bloating, and a significant impact on quality of life.
Common causes include low fiber intake, dehydration, and underlying medical conditions such as hypothyroidism or irritable bowel syndrome (IBS).

Symptoms often include infrequent bowel movements, straining, and hard stool consistency. If untreated, chronic constipation can lead to complications such as hemorrhoids, fecal impaction, or rectal prolapse.

Despite numerous products marketed for relief, from supplements to probiotics, patients often face confusion over what truly works. The new BDA guidelines aim to clarify which foods, drinks, and supplements offer scientifically validated benefits.

What the New BDA Guidelines Found

Researchers at King’s College London reviewed 75 randomized controlled trials involving various dietary and supplement interventions. Using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) framework, they developed 59 recommendations for clinicians and the public.
Only recommendations that achieved at least 85% expert consensus were included in the final guidelines.

Key evidence-backed dietary interventions include:

• Kiwifruit
  Eating two to three kiwifruit daily for at least four weeks was found to significantly increase stool frequency and ease bowel movements.
  Kiwi’s benefits are attributed to its fiber content and an enzyme called actinidin, which aids digestion and helps soften stool.
• High Mineral-Content Water
  Drinking 0.5 to 1.5 liters per day of mineral-rich water for 2–6 weeks was shown to improve stool consistency and promote bowel regularity.
  These waters, rich in magnesium and sulfate, draw water into the intestines, softening stools naturally.
• Rye Bread
  Consuming 6 to 8 slices daily for at least three weeks was associated with improved bowel function. While effective, researchers noted that achieving this intake might be challenging for some individuals.
• Magnesium Oxide Supplements
  Taking 0.5 to 1.5 grams daily for at least four weeks increased stool frequency and softened consistency, making it a viable nonfood intervention.

The study found limited evidence for the effectiveness of probiotics and senna supplements, both commonly used for constipation management.

Experts Welcome the Evidence-Based Clarity

Dr. Supriya Rao, a gastroenterologist and director of the Metabolic and Lifestyle Medicine Clinic at Integrated Gastroenterology Consultants, called the new guidelines “a meaningful upgrade.”

“Chronic constipation affects tens of millions of adults, yet most people only hear vague advice like ‘eat more fiber and drink water,’” Dr. Rao told Medical News Today.
“These guidelines separate what actually helps from what’s just tradition — offering specific foods, dosages, and timelines that have measurable effects.”

Dr. Ruvini Wijetilaka, a board-certified internal medicine physician and medical advisor for VSL Probiotics, agreed, adding:
“These recommendations help clinicians personalize treatment. Instead of general fiber advice, we can now recommend foods like kiwifruit and mineral water, which have proven benefits.”

Both experts emphasized the importance of trying one strategy at a time and tracking symptom changes, allowing patients and clinicians to identify the most effective dietary adjustments.

A Step Toward Clearer, Practical Gut Health Guidance

The new BDA guidelines provide clarity for patients and practitioners navigating the complex world of constipation management.
By focusing on specific, evidence-supported foods and natural remedies, the recommendations offer practical solutions for improving bowel health — and potentially reducing dependence on medications.

Source: Medical News Today – “Chronic constipation: Kiwi, mineral water may be best for providing relief”