Does sweet potato help with constipation?

It might, and nobody has tested it in people with ordinary chronic constipation. What is established is that fiber helps: across 16 randomized trials in adults with chronic constipation, 66 percent responded to a fiber supplement against 41 percent on control. Stool frequency improved only above 10 g of fiber a day. A medium sweet potato of 150 g has about 4.5 g. The only two sweet potato trials were small and done in Chinese hospital patients whose constipation came from chemotherapy or bed rest.

Unsettled. The answer stays open for a plain reason. No trial has given sweet potato to people with chronic constipation, and no systematic review has pooled it. What we have is indirect: fiber works, sweet potato contains fiber, and two hospital trials point the same way without numbers in their abstracts.

What the trials found

Fiber for chronic constipation

A 2022 meta-analysis of 16 randomized trials found fiber supplements raised the share of people who responded, a risk ratio of 1.48 with an interval from 1.17 to 1.88. In absolute terms that was 311 of 473 people on fiber and 134 of 329 on control. Psyllium and pectin had significant effects. The authors found benefit only above 10 g of fiber a day and over 4 weeks or more, and the trials varied a lot between themselves. These were supplements, mostly psyllium, and not whole foods.

Foods for constipation, with no sweet potato among them

A 2024 meta-analysis of 23 studies in 1714 adults with chronic constipation looked at kiwifruit, high-mineral water, prunes, rye bread, mango, figs, oat bran, yogurt and a few other foods. No sweet potato trial was among them. A 2026 network meta-analysis of 19 randomized trials in functional constipation found fruit-based foods raised how often people went more than fiber supplements or placebo, with moderate certainty. Its abstract does not name sweet potato. Root vegetables would sit in its vegetable groups, which ranked lower than fruit, and we could not get the full text to check.

The two sweet potato trials

In China, 120 leukemia patients starting their first chemotherapy were randomized to routine nursing care, 63 people, or routine care plus 7.1 oz (200 g) of sweet potato a day, 57 people. The authors report a lower constipation rate by day 2 and better bowel scores by day 5. The abstract gives no rates, the trial was not blinded, and we could not get the full text. This was about preventing drug-induced constipation during a short hospital stay.

The second trial randomized 93 hospital patients with acute coronary syndrome, 44 to a package of sweet potato, footbaths and acupressure and 49 to usual care. The package group had fewer cases of constipation and used fewer laxatives and enemas, again with no numbers in the abstract. Because sweet potato came bundled with two other treatments, this trial cannot tell what sweet potato did on its own.

One more small study touches the gut from a different side. In a survey of 45 people with gastroparesis, sweet potatoes were among the foods they could eat without symptoms. That is about stomach tolerance, and it says nothing about constipation.

Who should be careful

Not for everyone. People with kidney disease or on blood pressure drugs that hold on to potassium. A medium sweet potato carries about 720 mg of potassium, 481 mg per 3.5 oz (100 g). The NIH Office of Dietary Supplements says that in people with chronic kidney disease, or on ACE inhibitors or potassium-sparing diuretics, even food potassium below the adequate intake can push blood potassium too high.

Dried sweet potato concentrates that potassium. In Japan, two patients with kidney disease on angiotensin receptor blockers developed life-threatening heart rhythm problems after eating dried sweet potato, known as hoshi-imo, at 100 to 150 g a day. Their blood potassium reached 8.3 and 7.0 mEq/L, and both recovered after intensive care. It is a report of two cases.

More fiber brings more wind. In the same 16 fiber trials, flatulence was higher on fiber than on control, a standardized difference of 0.80 with an interval from 0.47 to 1.13. That is a relative measure with no absolute count of people behind it. In babies, sweet potato is a reported trigger of food protein-induced enterocolitis syndrome, a food allergy that shows as repeated vomiting. The evidence is one case report of an infant with three episodes, one of them from sweet potato.

What expert bodies say

The NIH digestive diseases institute, NIDDK, lists carrots, broccoli, green peas and collard greens as fiber-rich vegetables for constipation and advises adding fiber a little at a time. Sweet potato is not on the list. The page is patient advice without its own analysis and was last reviewed in May 2018. NIH ODS covers potassium in kidney disease, quoted above. We found no agency statement about sweet potato and constipation.

How we searched

What would change this answer

• A randomized trial of whole sweet potato at a stated dose, for 4 weeks or longer, in adults with chronic constipation, measuring how often people go and stool form. None was registered on ClinicalTrials.gov as of 7 October 2026.
• The full results of the two hospital trials, with the constipation rates in each group.
• The food list of the 2026 network meta-analysis, to see whether any sweet potato sits inside its vegetable groups.

Nutrition facts on the root itself are on the sweet potato page, and fiber in general is covered in the fiber guide.

Sources

1. ev-spcon-01 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 1251
   Overall, 311 of 473 (66%) participants responded to fiber treatment and 134 of 329 (41%) responded to control treatment [RR: 1.48 (95% CI: 1.17, 1.88; P = 0.001); I2 = 57% (P = 0.007)], with psyllium and pectin having significant effects.
   
   Who: adults with chronic constipation in RCTs of fiber supplementation
   Effect: response RR 1.48 (95% CI 1.17 to 1.88), I2 57%; stool frequency SMD 0.72 (0.36 to 1.08), only with doses >10 g/d and 4 weeks or longer; psyllium and pectin effective
   Certainty: Supplements (mostly psyllium), not whole foods; heterogeneity considerable. Gives the dose frame: one medium sweet potato is about 4.5 g fiber.
   Am J Clin Nutr, 2022 · checked 2026-10-07 · we read the abstract
2. ev-spcon-02 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 1251
   Flatulence was higher in fiber groups compared to control groups(SMD: 0.80; 95% CI: 0.47, 1.13; P < 0.00001).
   
   Who: adults with chronic constipation in RCTs of fiber supplementation
   Effect: flatulence SMD 0.80 (95% CI 0.47 to 1.13)
   Certainty: Supplement fiber; supports raising fiber from foods gradually.
   Am J Clin Nutr, 2022 · checked 2026-10-07 · we read the abstract
3. ev-spcon-03 · Meta-analysis or systematic review · systematic review and meta-analysis, RCT data synthesized · n = 1714
   We included 23 studies (17 RCTs, 6 uncontrolled; 1714 participants): kiwifruit (n = 7), high-mineral water (n = 4), prunes (n = 2), rye bread (n = 2), mango, fig, cereal, oat bran, yoghurt, water supplementation, prune juice, high-fibre diet, no-fibre diet (n = 1).
   
   Who: adults with chronic constipation in RCTs and uncontrolled trials
   Effect: fruits vs psyllium MD +0.36 BM/week (0.25 to 0.48); foods studied: kiwifruit, high-mineral water, prunes, rye bread, mango, fig, cereal, oat bran, yogurt and others, no sweet potato
   Certainty: Sweet potato absence shown by the list of included foods; search to July 2023; full text no_pmc.
   Aliment Pharmacol Ther, 2024 · checked 2026-10-07 · we read the abstract
4. ev-spcon-04 · Meta-analysis or systematic review · systematic review and Bayesian network meta-analysis of RCTs, search to August 2025 · n = 19 RCTs
   For defecation frequency, fruit-based foods (category 1) were better than fiber supplements (moderate certainty), mineral water (low certainty), and placebo (moderate certainty).
   
   Who: patients with functional constipation in RCTs of dietary interventions
   Effect: fruit-based foods better than fiber supplements and placebo for defecation frequency (moderate certainty); vegetables with whole grains inferior to fruit-based foods for stool consistency
   Certainty: Sweet potato not named in the abstract; root vegetables fall under vegetable categories, which ranked lower. Full text no_pmc.
   Am J Clin Nutr, 2026 · checked 2026-10-07 · we read the abstract
5. ev-spcon-05 · Randomized controlled trial(s) · randomized controlled trial, unblinded nursing intervention · n = 120
   Leukemia patients receiving their first chemotherapy were randomized to an intervention group (n = 57) or a control group (n = 63).
   
   Who: leukemia patients receiving their first chemotherapy, China; 57 sweet potato 200 g/d from admission to discharge vs 63 routine nursing
   Effect: lower constipation rate and more first defecation within 24 h on day 2; most Rome III items and satisfaction better on day 5; rates not given in the abstract
   Certainty: Short hospital stay, drug-induced constipation prevention, not chronic constipation; open label; full text paywalled (no_pmc), effect sizes not available.
   Cancer Nurs, 2016 · checked 2026-10-07 · we read the abstract
6. ev-spcon-06 · Randomized controlled trial(s) · prospective randomized controlled trial, three-part intervention · n = 93
   The study was a prospective, randomized controlled trial with a sample of 93 patients (SFA group, n = 44; usual care group, n = 49).
   
   Who: hospitalized patients with acute coronary syndromes, China; 44 SFA package vs 49 usual care
   Effect: fewer constipation cases, less laxative and enema use, better bowel-emptying satisfaction; numbers not given in the abstract
   Certainty: Sweet potato confounded with footbath and acupressure; bed rest population; full text paywalled (no_pmc).
   Gastroenterol Nurs, 2012 · checked 2026-10-07 · we read the abstract
7. ev-spcon-07 · Observational data · national food composition dataset · n = —
   Sweet potato, NFS, FNDDS code 73401000, fdc_id 2709697: Fiber, total dietary 3 G per 100 g; 1 medium 150 g, 4.5 G; 1 large 235 g, 7.0 G
   
   Who: food composition, US survey food code
   Effect: fiber 3 g/100 g; small 80 g = 2.4 g; medium 150 g = 4.5 g; large 235 g = 7.0 g; 1 cup mashed 250 g = 7.5 g
   Certainty: A 200 g trial portion gives about 6 g fiber, below the >10 g/d threshold where fiber supplements worked.
   USDA FNDDS, food code 73401000, Sweet potato, NFS (fdc_id 2709697) · checked 2026-10-07 · we read the dataset
8. ev-spcon-08 · Position of an expert body · agency patient guidance · n = —
   vegetables, such as carrots, broccoli, green peas, and collard greens
   
   Who: people with constipation (US patient guidance)
   Effect: vegetable examples: carrots, broccoli, green peas, collard greens; add fiber a little at a time
   Certainty: Patient advice without its own analysis; page last reviewed May 2018.
   NIDDK, Eating, Diet, & Nutrition for Constipation (NIH) · checked 2026-10-07 · we read the section
9. ev-spcon-09 · Observational data · national food composition dataset · n = —
   Sweet potato, NFS, FNDDS code 73401000, fdc_id 2709697: Potassium, K 481 MG per 100 g; 1 medium 150 g, 721.5 MG; 1 large 235 g, 1130.3 MG
   
   Who: food composition, US survey food code
   Effect: potassium 481 mg/100 g; small 80 g = 385 mg; medium 150 g = 722 mg; large 235 g = 1130 mg
   Certainty: Relevant for people on potassium restriction (CKD, ACE inhibitors, ARBs, potassium-sparing diuretics).
   USDA FNDDS, food code 73401000, Sweet potato, NFS (fdc_id 2709697) · checked 2026-10-07 · we read the dataset
10. ev-spcon-10 · Position of an expert body · government fact sheet · n = —
    However, in people with impaired urinary potassium excretion due to chronic kidney disease or the use of certain medications, such as angiotensin converting enzyme (ACE) inhibitors or potassium-sparing diuretics, even dietary potassium intakes below the AI can cause hyperkalemia [11].
    
    Who: people with impaired urinary potassium excretion
    Effect: no UL for potassium in healthy people; hyperkalemia risk from food in CKD and with certain medicines
    Certainty: Agency statement; applies to all potassium-rich foods.
    NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
11. ev-spcon-11 · Laboratory or animal data · case series · n = 2
    We herein report two cases of potentially life-threatening arrhythmia due to hyperkalemia triggered by the excessive consumption of "Hoshi-Imo" (dried sweet potato).
    
    Who: 2 adults with chronic kidney disease on RAAS inhibitors, Japan
    Effect: serum potassium 8.3 and 7.0 mEq/L; sinus arrest and sine-wave QRS; both recovered after intensive care
    Certainty: Two cases; doses from Results of PMC9259324 (300 g over two days; 100 g daily for a month). Dried sweet potato concentrates potassium.
    Internal Medicine (Tokyo). 2022 · checked 2026-10-07 · we read the fulltext
12. ev-spcon-12 · Laboratory or animal data · case report · n = 1
    We present a case of an infant who had three acute FPIES episodes: the first was at 5 months of age after chewing on a cellophane wrapper, the second was due to sweet potato, and the third was due to rice cereal.
    
    Who: 1 infant with food protein-induced enterocolitis syndrome
    Effect: acute FPIES episodes after rice contact, sweet potato and rice cereal
    Certainty: Single case; FPIES to weaning foods shows as repeated vomiting, not constipation.
    Eur J Pediatr, 2014 · checked 2026-10-07 · we read the abstract
13. ev-spcon-13 · Observational data · cross-sectional patient survey · n = 45
    Twelve additional foods were tolerated by patients (not provoking symptoms): ginger ale, gluten-free foods, tea, sweet potatoes, pretzels, white fish, clear soup, salmon, potatoes, white rice, popsicles, and applesauce.
    
    Who: adults with gastroparesis (39 idiopathic), food toleration survey
    Effect: tolerated foods included ginger ale, tea, sweet potatoes, potatoes, white rice, applesauce
    Certainty: Self-report; about upper GI tolerance, not constipation.
    Dig Dis Sci, 2015 · checked 2026-10-07 · we read the abstract