Several everyday foods and drinks have solid evidence behind them for getting your bowels moving, including prunes, kiwifruit, coffee, high-fiber foods, fermented dairy, and plain water. The catch is that different options work through different mechanisms, so the best choice depends on whether your issue is occasional sluggishness, chronically hard stools, or something more specific. What follows covers the options with the strongest research support, along with a few that sound promising but deserve a reality check.
Prunes and Prune Juice
If there is a single food most associated with bowel regularity, it is the prune. The reason prunes work so well is not just their fiber content. They contain a combination of sorbitol (a sugar alcohol that draws water into the intestine), pectin (a type of soluble fiber), and polyphenols, all of which contribute to their laxative effect. A randomized, placebo-controlled trial found that prune juice containing these three components softened hard stools and improved subjective constipation complaints compared to placebo.1PubMed Central. Prune Juice Containing Sorbitol, Pectin, and Polyphenol Ameliorates Subjective Complaints and Hard Feces While Normalizing Stool in Chronic Constipation: A Randomized Placebo-Controlled Trial Whole prunes and prune juice both deliver these compounds, though whole prunes give you more fiber per serving. A handful of prunes (about five or six) or a small glass of prune juice in the morning is a reasonable starting point. Some people notice effects within hours; for others, it takes a day or two of consistent intake.
Kiwifruit
Kiwifruit has become a bit of a darling in gut-health research over the past decade, and the evidence is genuinely interesting. A systematic review and meta-analysis found that kiwifruit and kiwifruit extracts may increase the number of weekly bowel movements, and when compared head-to-head with psyllium (one of the most commonly recommended fiber supplements), kiwifruit performed at least as well, with some evidence it produced softer stools.2PubMed Central. Kiwifruit and Kiwifruit Extracts for Treatment of Constipation: A Systematic Review and Meta-Analysis Beyond frequency, the same analysis found moderate evidence that kiwifruit reduced abdominal pain. The active components include actinidin (an enzyme that aids protein digestion), soluble fiber, and a high water content. Two green kiwifruits a day is the dose most commonly studied. One practical advantage of kiwifruit over supplements is that most people find it pleasant to eat, which helps with consistency.
Coffee
The urge to visit the bathroom after your morning coffee is not just in your head. Coffee stimulates motor activity in the rectum and sigmoid colon, and it does so remarkably fast. Research has shown that coffee can increase rectosigmoid muscle activity within about four minutes of drinking it, producing effects on the colon comparable to those of a full meal.3PubMed. Coffee and gastrointestinal function: facts and fiction. A review This is not purely a caffeine effect, either. Decaffeinated coffee also stimulates the gut, though usually to a lesser degree. Coffee appears to trigger the release of certain hormones (including gastrin and cholecystokinin) that promote colon contractions, and it may have direct effects on the smooth muscle lining the digestive tract.4PubMed Central. Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain-Gut Axis
That said, coffee is a better acute fix than a long-term constipation remedy. If you are already dehydrated, the mild diuretic effect of caffeine can work against you. And for people with sensitive stomachs or acid reflux, coffee may create more problems than it solves. But for someone with sluggish mornings and no underlying GI issues, a cup of coffee is one of the fastest-acting options available.
Water and Fluid Intake
The advice to “drink more water” for constipation can feel frustratingly vague, but the data behind it is actually quite strong. A large cross-sectional study of U.S. adults found that higher total moisture intake was linked to meaningfully lower constipation risk, with people in the highest intake group having roughly half the odds of constipation compared to people in the lowest group.5PubMed Central. The Association of moisture intake and constipation among us adults: evidence from NHANES 2005–2010 The relationship was dose-dependent: more fluid, less constipation, across the entire range of intake levels studied.
This does not mean that chugging extra glasses of water when you are already well-hydrated will suddenly make you regular. The benefit seems most pronounced for people who are currently on the low end of fluid intake. If your stools are hard and dry, increasing your water intake is one of the simplest interventions to try before reaching for anything else. Fiber in particular needs adequate water to work properly. Adding fiber supplements without enough fluid can actually make constipation worse, because the fiber absorbs available water and forms a drier, harder mass.
Mineral Water
Not all water is equal in this context. Mineral water naturally rich in magnesium sulfate has a mild laxative effect that goes beyond basic hydration. Magnesium sulfate draws water into the intestinal space through osmotic pressure, which increases the bulk and softness of stool and triggers the intestinal wall to contract.6PubMed Central. Efficacy and safety of a natural mineral water rich in magnesium and sulphate for bowel function: a double-blind, randomized, placebo-controlled study A separate trial found that a magnesium-sulfate-rich mineral water reduced the number of hard or lumpy stools and decreased the need for rescue laxatives in people with functional constipation.7PubMed. Efficacy and safety of a magnesium sulfate-rich natural mineral water for patients with functional constipation If you have access to a naturally high-magnesium mineral water, drinking it regularly is a gentle strategy. The magnesium content varies widely between brands, so check the label.
Does Water Temperature Matter?
There is a folk belief that warm water on an empty stomach helps move things along. The evidence here is mixed but worth knowing about. A study on water temperature and gastric motility found that warm water (around 60°C) led to more frequent stomach contractions than very cold water (around 2°C).8PubMed Central. The effects of water temperature on gastric motility and energy intake in healthy young men However, another study found that both cold and warm drinks actually suppressed the wave-like muscle contractions that push food from the stomach into the small intestine, slowing the rate at which contents moved through.9Gut. Effect of drink temperature on antropyloroduodenal motility and gastric electrical activity in humans The upshot: temperature may affect how your stomach handles liquids, but neither extremely hot nor extremely cold water has a clear advantage for relieving constipation. Body-temperature or mildly warm water is probably the safest bet if you want to avoid any braking effect on digestion.
Fermented Foods and Probiotics
Yogurt, kefir, sauerkraut, kimchi, and other fermented foods introduce live bacteria that can influence your gut environment. A small pilot study found that kefir supplementation sped up colonic transit and improved bowel satisfaction scores in people with chronic constipation.10PubMed. Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: a pilot study More broadly, a systematic review and meta-analysis of randomized controlled trials found that probiotic-containing products reduced intestinal transit time overall. Interestingly, the specific probiotic species, the number of strains, and the daily dose did not significantly influence the outcome. Larger trials tended to show bigger effects.11PubMed Central. Effects of probiotic-containing products on stool frequency and intestinal transit in constipated adults: systematic review and meta-analysis of randomized controlled trials
This is encouraging, but it also means the research has not zeroed in on a single “best” probiotic for constipation. If you want to try this route, kefir and natural yogurt with live cultures are the easiest food-based options. Probiotic supplements are another avenue, though you are often paying more for what fermented dairy provides naturally. Give any probiotic approach at least two to four weeks to assess whether it is making a difference, since gut microbial shifts take time.
Fiber-Rich Foods and Supplements
Fiber is the backbone of most dietary constipation advice, and for good reason. It adds bulk to stool, holds water, and helps waste move through the colon. But the type of fiber matters more than most people realize.
Psyllium husk is one of the best-studied fiber supplements. It has a high water-holding capacity and forms a gel in the intestine, which softens stool and makes it easier to pass.12PubMed Central. The Effect of Psyllium Husk on Intestinal Microbiota in Constipated Patients and Healthy Controls Its gel-forming ability also contributes to benefits beyond bowel function, including blood sugar and cholesterol management.13PubMed. Psyllium Husk: A Comprehensive Review of its Functional Properties, Health Benefits, Mechanisms of Action, and Potential Adverse Effects Psyllium is available as a powder you mix into water or smoothies, and it is the active ingredient in many over-the-counter fiber supplements.
Whole-food sources of fiber include legumes (lentils, chickpeas, black beans), oats, flaxseed, chia seeds, and vegetables like broccoli and Brussels sprouts. Flaxseed and chia seeds are particularly interesting because their outer coating produces a mucilage, a gel-like substance that adds lubrication in the digestive tract while also acting as a prebiotic, supporting the growth of beneficial gut bacteria.14ScienceDirect (Future Foods). Seeds for gut health: Prebiotic potential of seed mucilages from Chia, Fenugreek, Basil, Mustard, and Flaxseed and their impact on adult and toddler’s gut microbiome Ground flaxseed tends to work better than whole seeds, since your body cannot break down the intact seed coat easily.
Olive Oil and Dietary Fats
A tablespoon of olive oil on an empty stomach is a traditional Mediterranean remedy for constipation, and there is some physiological logic behind it. Olive oil stimulates the release of cholecystokinin, a hormone that triggers bile release and promotes gut contractions. Compared to diets heavy in other types of fat, olive oil also suppresses gastric acid secretion, which may be gentler on the digestive tract overall.15Grasas y Aceites. Digestion and absorption of olive oil The fat itself can also soften stool by providing a degree of lubrication as it passes through.
This is not a high-powered laxative. If you are severely constipated, olive oil alone probably will not be enough. But as part of a broader diet that includes adequate fiber and fluids, regularly consuming healthy fats (olive oil, avocado, nuts) supports smoother digestion. People on very low-fat diets sometimes experience harder stools for exactly this reason: they have removed a component that naturally assists transit.
Sugar Alcohols and Sweeteners
If you have ever eaten too many sugar-free candies and experienced urgent gastrointestinal consequences, you have already encountered the laxative effect of sugar alcohols. Sorbitol, which occurs naturally in prunes and is also used as an artificial sweetener, draws water into the colon through osmotic pressure. Among the sugar alcohols, sorbitol exerts a particularly strong osmotic load, which is why it tends to produce more noticeable laxative effects than alternatives like lactitol.16PubMed Central. Effects of Sweeteners on the Gut Microbiota: A Review of Experimental Studies and Clinical Trials – Section: Polyols
This is a double-edged mechanism. In small amounts, sorbitol-containing foods (prunes, pears, apples, sugar-free gum) can gently nudge your bowels along. In larger amounts, they can cause cramping, gas, and diarrhea. This is not a side effect so much as an overdose of the intended effect. If you are using prunes for constipation relief, start with a moderate portion and increase gradually. And if you have ever wondered why sugar-free foods carry that infamous warning about “excessive consumption may have a laxative effect,” now you know: the polyols are doing exactly what they were designed to do, just more aggressively than you asked for.
When Fiber Backfires
Fiber is the default recommendation for constipation, but it can make things worse for certain people, especially if it is introduced too quickly or if the wrong type is chosen. Even when used carefully, fiber can worsen bloating, gas, and abdominal discomfort.17American Journal of Gastroenterology. Fiber and Functional Gastrointestinal Disorders This is particularly true of highly fermentable, short-chain soluble fibers like oligosaccharides (found in foods like onions, garlic, and wheat), which can cause rapid gas production and pain in people with irritable bowel syndrome.18PubMed Central. Dietary fiber in irritable bowel syndrome
For people with IBS and constipation, soluble fiber like psyllium or inulin tends to be better tolerated than insoluble fiber (wheat bran, raw vegetables), and increasing intake gradually gives the gut time to adjust.19PubMed Central. Constipation-Predominant Irritable Bowel Syndrome (IBS-C): Effects of Different Nutritional Patterns on Intestinal Dysbiosis and Symptoms If adding fiber to your diet consistently makes your symptoms worse rather than better after a couple of weeks, this is worth mentioning to a doctor. Not all constipation responds to fiber. Slow-transit constipation and pelvic-floor dysfunction, for example, often need different interventions entirely.
Putting a Routine Together
Individual foods help, but the people who have the easiest time staying regular tend to combine several of these strategies rather than relying on a single one. A reasonable approach looks something like this: ensure you are drinking enough fluids throughout the day, include a mix of soluble and insoluble fiber from whole foods, eat some fruit (prunes or kiwifruit are the best-supported choices), and do not shy away from healthy fats. Coffee in the morning can provide an additional push. Fermented foods are a worthwhile addition for their broader gut-health benefits, even if their direct laxative effect is modest.
One important principle: consistency beats intensity. Eating a giant bowl of bran one day and then ignoring fiber for the next three is less effective than spreading moderate amounts across every day. Your gut microbiome adapts to what you feed it regularly, and the bacteria that produce short-chain fatty acids (which help stimulate colonic contractions) thrive on a steady supply of fermentable fiber.
Beyond Food and Drink
Diet is the most direct lever you can pull, but your body position on the toilet also plays a surprising role. The standard sitting position on a Western toilet does not fully straighten the anorectal angle, which is the bend between the rectum and the anal canal. When you sit, that bend remains partially kinked, requiring more straining to pass stool. Squatting straightens this angle, raises rectal pressure, and relaxes the pelvic-floor muscles, making evacuation easier and faster.20PubMed Central. Implementation of a Defecation Posture Modification Device Impact on Bowel Movement Patterns in Healthy Subjects
You do not need to install a squat toilet. A simple footstool placed in front of the toilet achieves a similar effect by raising your knees above your hips, which opens up the anorectal angle. Studies have found that these devices can reduce straining, shorten the time spent on the toilet, and improve the sensation of complete emptying, though results vary across different groups.21PubMed Central. Sitting vs. squatting: a scoping review of toilet postures and associated health outcomes One study in older adults with obstructed defecation found that a footstool reduced evacuation time and increased rectal pressure, particularly when the person leaned their upper body forward. For something that costs a few dollars and requires zero dietary changes, a toilet footstool is one of the easiest interventions to try alongside adjustments to what you eat and drink.