LONDON — Kiwis may soon be a staple on grocery lists for people struggling with chronic constipation. New evidence-based dietary guidelines from the British Dietetic Association (BDA), published Monday, identify kiwis, rye bread, and specific supplements as effective tools for improving bowel regularity — marking the first comprehensive, research-backed recommendations focused on dietary management rather than medication.
A Global Health Burden
Chronic constipation affects roughly 16% of adults worldwide, according to the American College of Gastroenterology, accounting for nearly 2.5 million doctor visits annually in the U.S. alone.
Despite its prevalence, treatment guidelines have historically centered on pharmaceuticals rather than food-based solutions — a gap that the new BDA guidance aims to fill.
Lead author Eirini Dimidi, a registered dietitian and associate professor at King’s College London, said existing recommendations to “eat more fiber” and “drink more water” were too vague and lacked scientific rigor.
“I remember looking at the guidelines and realizing how limited they were,” she said. “We needed clear, evidence-based advice clinicians and patients could trust.”
Reviewing the Evidence
To develop the new guidelines, researchers systematically analyzed clinical trials to assess which dietary strategies effectively manage chronic constipation. The results were published jointly in the Journal of Human Nutrition & Dietetics and Neurogastroenterology & Motility.
Constipation is defined as fewer than three bowel movements per week and is considered chronic if symptoms persist for more than three months. Common complaints include hard or lumpy stools, abdominal pain, and nausea. Severe cases can interfere with physical activity, mood, and quality of life, experts say.
Understanding the Condition
“Chronic constipation affects people across the lifespan,” said Sue-Ellen Anderson-Haynes, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. “I see it in toddlers, school-age children, and adults.
It’s not only uncomfortable — it can impact mood, productivity, and even participation in physical activity.”
Underlying causes range from dietary habits and sedentary lifestyles to certain medications and health conditions. Addressing these factors, experts agree, often requires a combination of nutritional, behavioral, and medical approaches.
Why Traditional Guidance Falls Short
Most U.S. recommendations focus heavily on medical therapies like laxatives or prescription drugs such as bisacodyl, senna, and amitiza, noted Dr. William Chey, a gastroenterologist at the University of Michigan and incoming president of the American College of Gastroenterology.
While these medications can help, he said, there’s growing recognition that food-based approaches should be first-line treatments.
Although increasing dietary fiber is a common suggestion, Dimidi said research linking a high-fiber diet to improved constipation outcomes is surprisingly limited. “There’s strong evidence that fiber benefits overall gut health,” she said.
“But when it comes specifically to constipation, we simply don’t have enough high-quality data to make broad claims.”
What the New Guidelines Recommend
The BDA’s new recommendations highlight six dietary interventions that can safely and effectively ease chronic constipation:
- Fiber supplements: More than 10 grams per day of fiber supplements, such as psyllium, can improve stool frequency and reduce straining. Start with a small amount and increase gradually.
- Probiotics: Strains like B. lactis and Bacillus coagulans may improve symptoms in some individuals. They should be taken daily for at least four weeks following product instructions.
- Magnesium oxide supplements: Doses of 0.5–1.5 grams per day can relieve bloating and abdominal pain while improving stool frequency.
- Kiwis: Eating three kiwis daily, with or without the skin, can enhance bowel frequency, though not necessarily stool consistency.
- Rye bread: Six to eight slices daily may improve regularity, though this level may be impractical for many people.
- High mineral-content water: Consuming 0.5–1.5 liters per day may aid digestion due to its magnesium content, a natural laxative.
Caution on Probiotics and Broader Impact
Chey, who was not involved in developing the guidelines, called them “a valuable road map for people managing constipation while waiting to see their physician.” However, he cautioned that probiotics may not work universally.
“The human microbiome varies by diet, genetics, and environment,” he said. “It’s difficult to generalize which strains will help.”
Still, Chey and Dimidi agreed the new recommendations offer an empowering approach for patients and clinicians alike. “We hope this guidance gives people evidence-based tools to manage their symptoms and improve quality of life,” Dimidi said. “It’s about helping patients feel in control again — naturally.”
