What foods help with constipation?

USDA FoodData Central. Daily Value for fiber: 28 g. Foods tested in constipation trials come first, then other high-fiber foods, with white rice for contrast.

• Level E The British Dietetic Association in 2025 strongly recommends psyllium for chronic constipation, while rating the evidence low and advising against polydextrose and GOS. Neurogastroenterol Motil, 2025

Text in quotation marks is word for word from the official source. Level E means the position of an expert body or a drug label. How we grade evidence.

Evidence behind the advice

• Level B In a 3-country crossover RCT, eating 2 green kiwifruits a day for 4 weeks added 1.53 complete bowel movements a week in functional constipation and 1.73 in IBS-C. Am J Gastroenterol, 2023, Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort
• Level B In a crossover RCT on 40 constipated adults, 3.5 oz (100 g) of prunes a day gave more complete bowel movements than psyllium at the same 6 g of fiber. Aliment Pharmacol Ther, 2011
• Level B In 84 Japanese adults with chronic constipation, 1.9 oz (54 g) of prune juice a day cut hard stools versus placebo within 3 weeks. Am J Gastroenterol, 2022
• Level A Across 16 RCTs with 1,251 adults with chronic constipation, 66% responded to fiber supplements against 41% on control, a 48% higher chance of relief. Am J Clin Nutr, 2022
• Level B In 59 women with self-reported constipation, three weeks of fiber-rich rye bread shortened intestinal transit time by 0.7 days (95% CI -1.1 to -0.2) and also raised gastrointestinal symptom scores by 1.6 points. Eur J Clin Nutr, 2006

The other side and the limits

• Level A The 2025 British Dietetic Association guideline pooled 2 randomized trials in 86 people with chronic constipation and found prunes did not soften stools more than psyllium, with very low certainty. J Hum Nutr Diet, 2025
• Level A In the British Dietetic Association meta-analysis, kiwifruit did not give more people a clinical benefit than psyllium (2 RCTs, 184 people, RR 1.32, 95% CI 0.91 to 1.92). J Hum Nutr Diet, 2025
• Level A A 2023 meta-analysis of RCTs found kiwifruit supplements, as opposed to the whole fruit, did not change stool frequency (3 RCTs, MD 0.24 bowel movements a week, 95% CI -0.32 to 0.80). Neurogastroenterol Motil, 2023
• Level A In people without constipation, 113 RCTs show only a small laxative effect: each extra gram of fiber a day adds about 0.05 bowel movements a week. Am J Clin Nutr, 2026
• Level A For chronic constipation, fiber supplements worked in two thirds of people against four in ten on control, and flatulence went up with them. van der Schoot et al., American Journal of Clinical Nutrition, 2022

Levels: A is a meta-analysis of trials, B a randomized trial, C an observational study, D lab work or case reports, E an expert position. How we grade evidence.

If you want to try food first, the trials point to two green kiwis a day or about 10 prunes a day, each for a few weeks. Both held up against psyllium in head-to-head trials. Rye bread also helped in one trial but raised gut symptoms.

Expect some gas. In the fiber trials, it went up along with relief. Split peas, lentils, black beans, raspberries and chia seeds give the most fiber per serving in the table.

Kiwi supplements, such as capsules and powder sachets, are not the same as the fruit: the meta-analysis below found they did not change stool frequency. If constipation is new, lasts for weeks, or comes with blood or weight loss, see a doctor.

Evidence behind this note

1. Level B In a 3-country crossover RCT, eating 2 green kiwifruits a day for 4 weeks added 1.53 complete bowel movements a week in functional constipation and 1.73 in IBS-C. Am J Gastroenterol, 2023, Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort
2. Level B In a crossover RCT on 40 constipated adults, 3.5 oz (100 g) of prunes a day gave more complete bowel movements than psyllium at the same 6 g of fiber. Aliment Pharmacol Ther, 2011
3. Level A The 2025 British Dietetic Association guideline pooled 2 randomized trials in 86 people with chronic constipation and found prunes did not soften stools more than psyllium, with very low certainty. J Hum Nutr Diet, 2025
4. Level A For chronic constipation, fiber supplements worked in two thirds of people against four in ten on control, and flatulence went up with them. van der Schoot et al., American Journal of Clinical Nutrition, 2022
5. Level A In the British Dietetic Association meta-analysis, kiwifruit did not give more people a clinical benefit than psyllium (2 RCTs, 184 people, RR 1.32, 95% CI 0.91 to 1.92). J Hum Nutr Diet, 2025
6. Level B In 59 women with self-reported constipation, three weeks of fiber-rich rye bread shortened intestinal transit time by 0.7 days (95% CI -1.1 to -0.2) and also raised gastrointestinal symptom scores by 1.6 points. Eur J Clin Nutr, 2006
7. Level A A 2023 meta-analysis of RCTs found kiwifruit supplements, as opposed to the whole fruit, did not change stool frequency (3 RCTs, MD 0.24 bowel movements a week, 95% CI -0.32 to 0.80). Neurogastroenterol Motil, 2023

Written from the positions and data on this page, reviewed by the Bioma editorial system. How we verify.

• What to eat with diverticulitis
• Dietary fiber: what it does and how much you need
• Prune juice: what the research says
• Rye bread: what the research says
• Chia seeds: what the research says
• Lentils: what the research says