Does cheese cause constipation?

Nobody knows for cheese on its own, because no randomized trial has tested it. The closest adult evidence is a 6-week randomized crossover trial in 46 overweight adults aged 45 to 65. A high-dairy diet that included at least one 1.1 oz (30 g) portion of low-fat cheese a day made stools harder than a low-dairy diet, a mean Bristol score of 3.29 against 3.88, and 8 people became constipated. Stool consistency was a secondary outcome of a trial about glucose, and the cheese cannot be separated from the milk, buttermilk and yogurt eaten alongside it.

Unsettled. The question has a clear answer only in a narrow group. In young children whose constipation does not respond to laxatives, removing all cow's milk helps some of them, and the 2026 pediatric guideline turns that into a 2 to 4 week trial when cow's milk allergy is suspected. For adults there is one trial of mixed dairy and no trial of cheese. A 2024 meta-analysis of foods and drinks for adult constipation gathered 23 studies in 1,714 people, and none tested cheese.

What the trials found

The best known trial is from 1998. Sixty-five children aged 11 to 72 months, referred to a gastroenterology clinic after laxatives had failed, drank soy milk and cow's milk for 2 weeks each under double-blind conditions. Forty-four of them, 68 percent, responded on soy milk and none responded on cow's milk. The group was unusual. Forty-nine of the 65 had anal fissures and the responders tended to have other signs of allergy, so this says little about a typical child with constipation.

Two smaller studies pull in different directions. In Australia, all 9 children who completed the soy milk period of a crossover trial had their constipation resolve, and a second trial in 39 children found no significant difference between A1 and A2 cow's milk. Allocation there was by odd or even birth date, the groups were small and many dropped out. In six Italian primary care practices, 11 young children whose constipation resisted laxatives tried a 4-week cow's milk protein free diet, and none of the 11 improved.

The pooled evidence is weak. A 2026 meta-analysis of non-drug treatments for childhood constipation found that adding a cow's milk free diet to the laxative PEG gave more children 3 or more stools a week, a risk ratio of 1.34 with an interval of 1.15 to 1.57. A single small trial sits behind that number, and the reviewers rated the certainty low because of very serious risk of bias. The paper does not give the absolute numbers for this outcome. An earlier 2022 meta-analysis of 52 trials in 4,668 children found a milk exclusion diet may help only in the subgroup where constipation could be a sign of cow's milk allergy, on the strength of 2 trials.

The one trial that put cheese in both arms tested something else. Thirty constipated women in Brazil ate 1.1 oz (30 g) a day of fresh cheese for 30 days, either plain or with the probiotic Bifidobacterium lactis Bi-07, and straining eased in the probiotic group. The abstract gives no effect size, and because both groups ate cheese it tells us about the probiotic.

The only data on cheese by name are observational. Among 344 children aged 6 to 48 months, those who ate cheese more than 5 days a week had 5.18 times the odds of functional constipation, with an interval from 1.58 to 16.93. Diet was reported by caregivers at a single visit and the analysis did not adjust for fiber or fluid, which is why this is a link and cannot show that cheese caused it.

Who should be careful

Not for everyone. Cutting out cow's milk is a real diet change for a small child. The 2026 ESPGHAN and NASPGHAN guideline says a child on a milk free diet should get advice from a dietitian, and that calcium supplements should be considered during the diet. It also says cow's milk allergy is rarely the main cause of constipation and is never its only symptom, so milk should not be cut on constipation alone.

For adults, the warning sign comes from the high-dairy trial. Five of the 46 healthy overweight adults developed severe constipation and 3 developed mild constipation over 6 weeks of 5 to 6 dairy portions a day. If you have moved to a much higher dairy intake and your stools have hardened, that trial is consistent with your experience, even though it cannot pin the change on cheese.

What expert bodies say

The 2026 joint guideline of the European and North American pediatric gastroenterology societies suggests a cow's milk free diet for 2 to 4 weeks as an add-on, only for children who have not responded to conventional treatment and only when cow's milk allergy is suspected. It is a conditional recommendation based on low certainty evidence. It covers all cow's milk and does not address cheese separately. We found no expert body that gives advice on cheese and constipation in adults.

How we searched

What would change this answer

• A randomized trial in adults that changes cheese intake alone, keeping fiber and fluid steady, with stool frequency and consistency as the main outcomes. Nothing like it is registered.
• A larger trial of a cow's milk free diet in children with laxative-resistant constipation, with proper allocation and absolute response rates, to replace the single small trial behind the pooled result.
• An observational study of cheese and constipation that adjusts for fiber and fluid, in adults as well as toddlers.

More on cheese, including what the evidence says on cholesterol and the rest: cheese →

Sources

1. ev-chcst-01 · Randomized controlled trial(s) · systematic review and meta-analysis of RCTs · n = 1 trial pooled for this outcome (Dehghani); 4 cow's milk free diet trials in the review
   CMFD as an addition to PEG may lead to more children with three or more bowel movements, and GRADE certainty was rated as low due to very serious risk of bias (RR: 1.34 (95% CI 1.15 to 1.57), moderate magnitude of effect) (figure 5).
   
   Who: children with functional constipation in randomized trials comparing a cow's milk free diet plus PEG with a normal diet plus PEG
   Effect: children with >=3 bowel movements/week RR 1.34 (95% CI 1.15 to 1.57), GRADE low certainty (very serious risk of bias); treatment success not estimable
   Certainty: tests removal of all cow's milk, cheese not studied separately; single small trial behind the pooled RR, so graded B as one RCT, not A
   BMJ Paediatrics Open, 2026 (Efficacy and safety of non-pharmacological treatments for paediatric functional constipation: a systematic review and meta-analysis) · checked 2026-10-07 · we read the fulltext
2. ev-chcst-02 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 4,668
   Meta-analyses for treatment success and/or defecation frequency, including 20 RCTs, showed abdominal electrical stimulation (n = 3), Cassia Fistula emulsion (n = 2), and a cow's milk exclusion diet (n = 2 in a subpopulation with constipation as a possible manifestation of cow's milk allergy) may be effective.
   
   Who: children aged 2 weeks to 18 years with functional constipation in randomized trials of non-drug treatments
   Effect: cow's milk exclusion diet may be effective for treatment success or defecation frequency (2 RCTs, subgroup with suspected cow's milk allergy); overall high risk of bias
   Certainty: no pooled number in the abstract; full text not in PMC
   J Pediatr, 2022 · checked 2026-10-07 · we read the abstract
3. ev-chcst-03 · Randomized controlled trial(s) · double-blind crossover trial · n = 65
   Forty-four of the 65 children (68 percent) had a response while receiving soy milk.
   
   Who: children aged 11 to 72 months with chronic constipation referred to a pediatric gastroenterology clinic, previously treated with laxatives without success
   Effect: response (>=8 bowel movements per 2 weeks) 44/65 (68%) on soy milk vs 0 on cow's milk
   Certainty: highly selected referral sample, 49 of 65 with anal fissures; responders had other allergic signs; whole milk tested, not cheese
   New England Journal of Medicine, 1998, 339(16):1100-1104 (Iacono, Cavataio, Montalto et al.) · checked 2026-10-07 · we read the abstract
4. ev-chcst-04 · Randomized controlled trial(s) · randomized crossover trial · n = 46
   There were 5 subjects that developed severe constipation and 3 subjects who developed mild constipation during the HDD (Bristol stool chart score of 1 or 2).
   
   Who: healthy overweight adults aged 45-65 (BMI 25-30), low-medium dairy consumers; 5-6 dairy portions/day incl. at least 1 portion of 1.1 oz (30 g) low-fat cheese vs <=1 portion/day
   Effect: Bristol stool score 3.29 +/- 1.13 on high-dairy vs 3.88 +/- 0.81 on low-dairy (p < 0.001); 5 severe and 3 mild constipation on high-dairy
   Certainty: stool consistency a secondary outcome of a glucose-metabolism trial; mixed dairy (milk, buttermilk, yogurt, cheese), cheese effect not separable
   Nutrients, 2020 · checked 2026-10-07 · we read the fulltext
5. ev-chcst-05 · Randomized controlled trial(s) · randomized crossover trial · n = 46
   Notably, mean stool consistency score was 3.88 ± 0.81 during the LDD and 3.29 ± 1.13 during the HDD (p < 0.001).
   
   Who: healthy overweight adults aged 45-65 in a randomized crossover high- vs low-dairy diet, 6 weeks each
   Effect: Bristol score 3.29 +/- 1.13 vs 3.88 +/- 0.81, p < 0.001
   Certainty: secondary outcome; mixed dairy
   Nutrients, 2020 · checked 2026-10-07 · we read the fulltext
6. ev-chcst-06 · Randomized controlled trial(s) · randomized controlled trial · n = 30
   After 30 days we observed that the ingestion of fresh cheese enriched with Bifidobacterium lactis Bi-07 promoted benefic effects on the symptoms of strength to evacuate.
   
   Who: constipated women (Rome III), Brazil, mean age about 38-41; 30 g/day fresh cheese with B. lactis Bi-07 vs regular fresh cheese, 30 days
   Effect: improvement in straining to evacuate with probiotic cheese; no effect size in abstract
   Certainty: very small, no effect size; both arms ate cheese, so it tests the probiotic, not cheese itself
   Arq Gastroenterol, 2013 · checked 2026-10-07 · we read the abstract
7. ev-chcst-07 · Observational data · cross-sectional study · n = 344
   After adjustment for age, sex, and BMI z-score, frequent cheese consumption remained a risk factor (> 5 days/week: adjusted odds ratio (aOR) = 5.18, 95% CI: 1.58-16.93; 2-4 days/week: aOR = 3.10, 95% CI: 1.52-6.34), and daily fresh fruit intake was protective (aOR = 0.28, 95% CI: 0.14-0.59).
   
   Who: children aged 6-48 months at routine check-ups, City Children's Hospital, Southeast Asia; Rome IV functional constipation
   Effect: cheese >5 days/week aOR 5.18 (95% CI 1.58 to 16.93); 2-4 days/week aOR 3.10 (1.52 to 6.34); adjusted for age, sex, BMI z-score
   Certainty: cross-sectional, caregiver-reported diet, not adjusted for fiber or fluid; wide CI
   J Paediatr Child Health, 2026 · checked 2026-10-07 · we read the abstract
8. ev-chcst-08 · Observational data · blinded crossover trials, allocation by odd or even day of birth · n = 13 and 39
   The results of Trial 1 demonstrate an association between CFC and cow's milk consumption but Trial 2 failed to show an effect from type of casein.
   
   Who: children aged 18-144 months (Trial 1, n=13) and 21-144 months (Trial 2, n=39) with chronic functional constipation, 2-week milk periods
   Effect: Trial 1: 9/9 soy completers resolved; Trial 2 resolution 81% washout, 79% A2, 57% A1, not significantly different
   Certainty: allocation by birth date, small, high dropout; tests milk, not cheese
   Nutrients, 2013 · checked 2026-10-07 · we read the abstract
9. ev-chcst-09 · Observational data · case-control study with uncontrolled elimination diet · n = 11
   The 4-week trial of dietary elimination did not result in improvement in any of these 11 children.
   
   Who: children aged 6 months to 6 years with chronic constipation refractory to osmotic laxatives, six primary care practices, Italy
   Effect: 0/11 improved after 4-week cow's milk protein elimination
   Certainty: tiny uncontrolled subgroup; shows that most constipated children are not milk-sensitive
   Arch Dis Child, 2008 · checked 2026-10-07 · we read the abstract
10. ev-chcst-10 · Position of an expert body · clinical practice guideline (GRADE) · n = —
    Recommendation: A cow's milk‐free diet trial for 2–4 weeks is suggested as an adjunct treatment option for FC in children not responding to conventional therapy alone and when cow's milk allergy (CMA) is suspected.
    
    Who: children aged 0-18 years with functional constipation
    Effect: conditional recommendation, overall low certainty evidence, moderate effect size
    Certainty: society guideline; recommendation about all cow's milk, cheese not addressed separately
    J Pediatr Gastroenterol Nutr, 2026 · checked 2026-10-07 · we read the fulltext
11. ev-chcst-11 · Position of an expert body · clinical practice guideline (GRADE) · n = —
    Supplementation with calcium was used in trials and should be considered during a cow's milk‐free diet.
    
    Who: children with functional constipation on a cow's milk free diet trial
    Effect: dietitian counseling to prevent malnutrition; calcium supplementation should be considered
    Certainty: expert rationale within guideline
    J Pediatr Gastroenterol Nutr, 2026 · checked 2026-10-07 · we read the fulltext
12. ev-chcst-12 · Position of an expert body · clinical practice guideline (GRADE) · n = —
    While constipation can be one of the symptoms associated with CMA, it is rarely the primary cause of constipation, and constipation will never be the only symptom of CMA.
    
    Who: children with functional constipation
    Effect: cow's milk allergy rarely the primary cause; never the only symptom; diagnose from full history and examination
    Certainty: expert statement citing the ESPGHAN CMA guideline
    J Pediatr Gastroenterol Nutr, 2026 · checked 2026-10-07 · we read the fulltext
13. ev-chcst-13 · Meta-analysis or systematic review · systematic review and meta-analysis · n = 1,714
    There is a scarcity of evidence on foods, drinks and diets in constipation and further RCTs are needed.
    
    Who: adults with chronic constipation in intervention trials of foods, drinks and diets
    Effect: foods studied: kiwifruit, mineral water, prunes, rye bread, mango, fig, cereal, oat bran, yogurt and others; no cheese trial
    Certainty: absence of cheese inferred from the listed interventions
    Aliment Pharmacol Ther, 2024 · checked 2026-10-07 · we read the abstract