These 3 Foods May Help with Chronic Constipation

• A study from the British Dietetic Association suggests some foods can help with chronic constipation.
• Kiwi, rye bread and prunes offer food-based alternatives with proven constipation benefits.
• Not all fiber or probiotic types are helpful—some may even worsen symptoms.

Chronic constipation is more than just an occasional inconvenience; it’s a condition that affects more than 10% of the global population, significantly affecting quality of life and placing a financial strain on healthcare systems.

For many, the go-to advice has been to increase dietary fiber and drink more water. Yet, more than half of those affected remain dissatisfied with their treatment options, highlighting the need for better solutions. 

To address this gap, a team of experts from the British Dietetic Association has developed the first comprehensive, evidence-based dietary guidelines for managing chronic constipation. These guidelines aim to provide practical, research-backed recommendations that go beyond the traditional advice, and they are co-published in the Journal of Human Nutrition and Dietetics and Neurogastroenterology & Motility.

How Was the Study Conducted?

Researchers developed these dietary guidelines through a rigorous process that was spearheaded by a multidisciplinary Guideline Steering Committee of experts in nutrition, dietetics, gastroenterology and gut physiology. The team aimed to create recommendations for adults with chronic idiopathic constipation, focusing on dietary interventions such as supplements, specific foods, drinks and even whole diets.

To ensure the guidelines were rooted in robust evidence, the team conducted four systematic reviews and meta-analyses, analyzing data from 75 randomized controlled trials. These studies examined the effectiveness of various dietary interventions, including fiber and probiotic supplements, magnesium oxide, kiwifruit, rye bread and high mineral-content water. 

What Did the Study Find?

The study uncovered insights into which dietary interventions are effective for managing chronic constipation and which fall short. The researchers highlighted three foods in particular for their potential benefits for constipation: kiwi, prunes and rye bread. 

And among the most effective strategies, psyllium fiber emerged as a standout option. Psyllium increased stool frequency, improved stool consistency and reduced the severity of straining. The evidence showed that higher doses of psyllium (greater than 10 grams per day) were particularly effective, and benefits were observed regardless of whether the treatment lasted less than or more than four weeks. In contrast, other fiber types, such as inulin and polydextrose, showed little to no benefit, and some even worsened symptoms like flatulence.

Consuming two to three kiwifruits daily for at least four weeks was found to improve stool frequency and reduce abdominal pain. Interestingly, kiwifruit was shown to be as effective as psyllium fiber in some cases, making it a viable alternative for those who prefer a natural food option. However, the benefits of kiwifruit were primarily limited to stool frequency, with little impact on stool consistency or other symptoms.

Eating prunes also appears to be an effective remedy for managing constipation. When it comes to comparing prunes to psyllium fiber, two randomized controlled trials involving 86 participants showed no greater impact of prunes on stool consistency compared to psyllium, and similar results were observed for straining in another set of trials. For individuals who prefer a natural food-based option, prunes can be a reasonable choice.

Rye bread presented a more mixed picture. While it was more effective than white bread at increasing stool frequency, it also worsened global symptoms such as bloating and abdominal discomfort. This dual effect makes rye bread a less practical option for some individuals, particularly those who are sensitive to gastrointestinal discomfort. Note that the “dose” of rye bread evaluated was 6 to 8 slices per day, which can be a lot for many. It’s also worth noting that more processed rye breads, like the kind you’ll find on grocery store shelves, might not have the same fiber content as more traditional loaves.

Probiotics also showed promise, though the results were more nuanced. While probiotics as a general category were found to increase stool frequency and improve global symptoms, the evidence was inconsistent when it came to specific strains. For example, Bifidobacterium lactis and multi-strain probiotics demonstrated some benefits, but other strains showed no significant impact. 

Magnesium oxide also emerged as one of the more effective interventions in the study. It significantly increased stool frequency, softened stool consistency, and improved symptoms such as straining and bloating. Additionally, magnesium oxide was shown to enhance overall quality of life, making it a strong recommendation in the guidelines. The evidence supporting magnesium oxide was particularly robust, with moderate levels of certainty and strong recommendations from the expert panel. The authors specifically suggest a dose of 0.5-1.5 grams daily.

High mineral-content water was another intervention that showed promise, particularly in improving treatment response. Drinking 0.5 to 1.5 liters of high mineral-content water daily for two to six weeks increased the likelihood of a beneficial response to treatment. However, it had no significant impact on stool frequency, global symptoms or quality of life. The guidelines also noted that the high sodium content in some mineral waters could be problematic for individuals with dietary restrictions, such as those with hypertension.

What Not to Do for Chronic Constipation

The study also highlighted interventions that were less effective or even counterproductive. For example, senna supplements, despite their popularity, were found to have no significant impact on stool frequency or other constipation-related outcomes. Similarly, synbiotic supplements, which combine probiotics and prebiotics, showed no meaningful benefits. Surprisingly, no recommendations were made for whole diet approaches due to a lack of evidence. These findings underscore the importance of evidence-based recommendations, as they help patients avoid ineffective or potentially harmful treatments.

How Does This Apply to Real Life?

These guidelines co-published in the Journal of Human Nutrition and Dietetics and Neurogastroenterology & Motility offer a practical roadmap for managing chronic constipation through diet. Based on this data, people can now make more informed choices about which interventions to try based on their specific symptoms and preferences. Someone struggling with straining might benefit most from psyllium, while a person looking for a natural food option could consider kiwifruit. For those who experience bloating or other side effects from fiber supplements, magnesium oxide or high mineral-content water might be better alternatives.

Hydration remains a cornerstone of constipation management, but the guidelines provide a more nuanced perspective. High mineral-content water, for instance, can be a simple yet effective addition to a treatment plan, especially for those who struggle with traditional fiber supplements. However, patients should be mindful of the mineral content and choose waters that align with their dietary needs.

Bottom line? These guidelines empower people to make informed, evidence-based decisions tailored to individual needs, which can offer relief from vague recommendations like “increase fiber intake.”

Our Expert Take

These guidelines mark a significant step forward in the dietary management of chronic constipation. Unlike previous recommendations that focused narrowly on fiber and water, this comprehensive approach considers a broader range of interventions, backed by rigorous scientific evidence. However, it’s important to note that most of the findings are based on low to moderate levels of evidence, underscoring the need for further research.

That said, the guidelines are not a one-size-fits-all solution. Individual factors like dietary restrictions, co-morbidities and personal preferences should always be considered. For example, while magnesium oxide is highly effective, it may not be suitable for individuals on low-magnesium diets. Similarly, the higher sodium content in some mineral waters could be problematic for those with hypertension.