Chronic constipation is more than an occasional nuisance. In the guidelines, it’s described as unsatisfactory defecation due to infrequent stools, difficult stool passage, or both.
It affects quality of life and is common worldwide (the paper cites a global prevalence of ~10.1%).
Most people try lifestyle changes first—especially diet—but many remain dissatisfied with results.
One reason: older guidance often stayed vague (“increase fiber,” “drink more fluids”) and left out other dietary strategies where evidence exists, or included recommendations without robust support.
📚 What’s new: The 2025 British Dietetic Association (BDA) dietary guidelines
These are presented as the first comprehensive, evidence-based dietary guidelines specifically for managing chronic constipation in adults. They were built using four systematic reviews/meta-analyses, then translated into recommendations using GRADE and a Delphi consensus process.
Key headline numbers from the paper: 75 randomized controlled trials (RCTs) were included across the reviews, 59 recommendation statements were generated and accepted.
Recommendations cover supplements, foods, and drinks—but no “whole-diet” approach (e.g., “high-fiber diet” as a general concept) received a recommendation due to lack of RCT evidence.
🥄 What the guidelines suggest is most worth trying (in real life)?
1) Fiber—but which fiber matters
The big shift is that the guideline doesn’t treat “fiber” as one thing.
- Different fibers behave differently, and the strongest, most consistent signal is for psyllium.
- The summary highlights psyllium as a recommended option to improve specific constipation outcomes.
Practical guidance from the recommendations:
- Doses above 10 g/day are considered “more optimal” in studies (better response).
- Fiber should be tried for at least 4 weeks before evaluating its effect.
- It should be introduced gradually (due to tolerance).
- And, where clinically appropriate, with additional fluid intake (water).
🌀 Important: Fiber may increase gas/flatulence, especially certain types (e.g., inulin-type fructans), so the pace of “introduction” is important.
2) Probiotics—may help, but it’s strain-specific and not universal
Guidelines suggest that probiotics overall may increase the likelihood of clinical improvement, but it is often unclear which exact strains are responsible for the effect.
For Bifidobacterium lactis, there is some signal that it may increase stool frequency (with a moderate level of evidence for this outcome), but in general there is no single probiotic solution that works for everyone.
Practical guidance from the recommendations:
- If a person wants to try a probiotic, one product of choice can be tested for at least 4 weeks, then its benefit should be evaluated.
3) Magnesium oxide—surprisingly “guideline-ready”
For magnesium oxide, the guidelines provide fairly clear messages:
- It may increase stool frequency and soften stool.
- It may improve global symptoms and reduce straining and the sensation of incomplete evacuation.
Practical guidance from the recommendations:
- As a general framework, 0.5–1.5 g/day for at least 4 weeks is suggested, with gradual dose escalation while monitoring tolerance.
⚠ Clinical note: This should always be individualized, especially in people with kidney problems, specific therapies, or a sensitive GI tract.
4) Senna — a surprise: “no clear effect” in these analyses
Although senna is popular, these guidelines report that in meta-analyses it did not show a clear impact on “clinical benefit” or stool frequency compared to placebo (with low certainty of evidence).
🍞 Food and beverages: specific items included in the guidelines
Kiwi
There is a practical, food-based recommendation:
- 2–3 kiwis per day for at least 4 weeks as an option for constipation.
Compared to psyllium, kiwi may slightly increase stool frequency, but it is not a “miracle solution” and effects are generally modest.
Prunes
Compared to psyllium, there is no clear advantage for stool consistency in available RCTs within these analyses.
This does not mean they “don’t work for anyone,” but rather that—based on strict evidence from this set of studies—they are not superior to an already proven effective option.
Rye bread
Rye bread is interesting because:
- It may increase stool frequency compared to white bread,
But it may also worsen global symptoms in some individuals (e.g., gas, bloating, discomfort),
And the “dose” used in studies was often quite high (e.g., 6–8 slices per day), which is not always practical in real life.
Mineral-rich water
Guidelines note that water with a high mineral content may help with “treatment response” over a certain period, but effects on other symptoms are not always clear.
Practical framework:
0.5–1.5 L/day for 2–6 weeks.
They also emphasize that there are no universal thresholds for what counts as “enough minerals,” and water composition varies.
📝 How to translate this into FORMULA ZDRAVLJA practice (without overload)
📌 First: safety check (“red flags”)
If there is blood in the stool, unexplained weight loss, significant pain, anemia, nighttime symptoms, or newly developed constipation that changes rapidly—this is a signal for medical evaluation and diagnostics, not just a “dietary experiment.”
🔁 Then: 4 weeks, one change at a time
The most common mistake is changing 5 things at once, so we don’t know what helped (or worsened things).
Example of a “4-week test” (from guidelines):
- Psyllium or kiwi as first-line (depending on tolerance), with gradual introduction and monitoring of gas/bloating.
- If choosing a probiotic: test for 4 weeks, then evaluate.
- If clinically appropriate: magnesium oxide as an option, with tolerance monitoring.
📒 Measure instead of guessing
A simple diary for 10 days before and 10 days during the change:
- stool frequency,
- straining / sensation of incomplete evacuation,
- bloating / pain.
Source: Eirini Dimidi, Alice van der Schoot, Kevin Barrett, Adam D. Farmer, Miranda C. Lomer, S. Mark Scott, Kevin Whelan. British Dietetic Association Guidelines for the Dietary Management of Chronic Constipation in Adults. Neurogastroenterology, 2025; DOI: 10.1111/nmo.70173
💚 THE HEALTH FORMULA – prevention and healing begins with understanding
In The HEALTH FORMULA constipation is not “just constipation.” It is a signal that bowel rhythm, microbiome, hydration, nervous regulation, and food choices are not in optimal balance.
That’s why we use what is proven to be helpful (e.g., psyllium, kiwi, magnesium oxide when needed, selective probiotics, mineral water), but apply it intelligently and in a personalized way—one change at a time, long enough to evaluate the effect, with tolerance monitoring.
The goal is not a “perfect diet,” but a routine that works for your body—because in health, consistency wins over extremes.
