Several drinks can help relieve constipation, ranging from simple water to prune juice, coffee, and fiber-rich smoothies. The best choice depends on whether you need gentle, everyday relief or something stronger for occasional use. Here’s what actually works and why.
Water: The Simplest Fix
Dehydration is one of the most common and overlooked causes of constipation. When your body doesn’t have enough fluid, it pulls more water from your colon, leaving stool hard and difficult to pass. Simply increasing your water intake can soften things up and get them moving again, especially if you’re not currently drinking enough.
There’s no magic number, but aiming for eight glasses a day is a reasonable baseline. Some small studies suggest warm water may help accelerate how quickly things move through the digestive tract, though the evidence isn’t conclusive. By the time water reaches your intestines, it’s already close to body temperature regardless of how you drank it. The temperature matters far less than the volume. If you’re constipated, drinking more water of any temperature is a solid first step.
Prune Juice
Prune juice is one of the most reliable natural laxatives, and it works through multiple mechanisms at once. Prunes contain both soluble and insoluble fiber (about 17.8 grams per 100 grams of whole prunes), which adds bulk to stool and softens it. They also contain sorbitol, a sugar alcohol your body absorbs slowly. Sorbitol draws water into the intestines through osmosis, which loosens stool and stimulates movement.
The laxative threshold for sorbitol varies by person. Research suggests it can take as little as 0.17 grams per kilogram of body weight in men and 0.24 grams per kilogram in women to produce a noticeable effect. A standard 8-ounce glass of prune juice contains roughly 15 grams of sorbitol, which is enough to cross that threshold for most adults. Start with half a glass if you’ve never tried it. Drinking too much at once can cause bloating, gas, or cramping.
Coffee
Coffee stimulates the colon in ways that go beyond just caffeine. A compound in coffee called furan triggers the release of gastrin, a hormone produced in the stomach lining that ramps up muscle contractions throughout your digestive tract. Caffeine itself also stimulates those contractions. On top of that, the warmth of the drink causes blood vessels to dilate and smooth muscle to relax, which can reduce resistance and speed things along.
The effect is strongest in the morning, when your body’s natural gastrocolic reflex (the urge to have a bowel movement after eating or drinking) is already at its peak. Coffee essentially amplifies a signal your body is already sending. If your colon is full and ready, the result can come within minutes of your first sip. That said, coffee is a mild diuretic, so it can work against you if you’re not drinking enough water alongside it. It’s best used as a complement to good hydration, not a replacement for it.
Kefir and Fermented Drinks
Kefir, a tangy fermented milk drink, contains a dense mix of beneficial bacteria and yeast that can influence how your gut processes waste. In a pilot study of 20 people with chronic functional constipation, drinking 500 milliliters (about two cups) of kefir daily for four weeks led to significantly increased stool frequency, improved stool consistency, and reduced need for laxatives. Participants with slow colonic transit, meaning waste moved through their systems unusually slowly, saw a measurable acceleration in transit time.
Kombucha and other fermented beverages contain probiotics too, though kefir has the strongest research behind it for constipation specifically. The effects aren’t instant. You’re essentially reshaping your gut bacteria over days to weeks, so fermented drinks work best as a daily habit rather than a one-time fix.
Fiber-Boosted Smoothies
Blending high-fiber ingredients into a smoothie is an effective way to increase your fiber intake in liquid form. Psyllium husk is one of the best-studied options. It’s a bulk-forming laxative that binds to partially digested food, absorbs water, and increases the size and moisture of your stool. In a study of 51 people with type 2 diabetes and constipation, taking 10 grams of psyllium twice daily reduced constipation along with body weight, blood sugar, and cholesterol.
Ground flaxseed works through a similar mechanism, adding both soluble fiber and omega-3 fatty acids. A tablespoon or two blended into a smoothie with fruit and water or milk can make a real difference over the course of a few days. The key with any fiber supplement is to increase your water intake at the same time. Fiber absorbs fluid to do its job, and adding fiber without enough liquid can actually make constipation worse.
A simple constipation-relieving smoothie might include a handful of spinach, a banana, a tablespoon of ground flaxseed, a teaspoon of psyllium husk, and a cup of water or kefir. The combination gives you fiber from multiple sources along with fluid and, if you use kefir, probiotics.
Senna Tea
Senna tea is a stronger option that works as a stimulant laxative. It contains compounds called sennosides that directly trigger contractions in the colon wall, physically pushing waste through. It’s effective, but it’s not a casual daily drink. The Mayo Clinic notes that senna should not be used for more than one week without medical guidance, because prolonged use can cause your colon to become dependent on it for normal movement.
Senna tea typically produces a bowel movement within 6 to 12 hours, so many people drink it before bed and see results in the morning. It’s best reserved for occasional use when gentler methods haven’t worked.
Magnesium Citrate Solution
Liquid magnesium citrate is an over-the-counter saline laxative that works by drawing water into your intestines through osmosis, similar to sorbitol but more potent. The standard adult dose is 6.5 to 10 fluid ounces, taken with a full 8-ounce glass of water. It’s available at most pharmacies, often flavored with cherry or lemon.
This is one of the faster-acting options, typically producing results within 30 minutes to 6 hours. It’s effective for occasional constipation but isn’t meant for regular use. Drinking plenty of water alongside it is essential, since the mechanism depends on pulling fluid into your colon.
Aloe Vera Juice: Worth the Caution
Aloe vera juice has a long history as a natural laxative, and the active compounds responsible are anthraquinones, which stimulate the colon. However, this is one option where the safety concerns are significant. Research in animals has linked non-purified aloe vera extracts with high anthraquinone levels to increased rates of colon abnormalities, including precancerous changes. The FDA has banned anthraquinone-containing compounds from over-the-counter laxative drugs.
Commercially available aloe vera juice sold as a beverage (not a laxative) is typically purified and decolorized to remove most anthraquinones. These filtered versions are generally considered safer but also have little to no laxative effect. If you’re considering aloe vera juice specifically for constipation, the purified versions likely won’t do much, and the unpurified versions carry risks that make other options a better choice.
What to Try First
For mild or occasional constipation, start with the basics: more water throughout the day, a glass of prune juice, and your morning coffee. These are gentle, well-supported, and unlikely to cause problems. If you want longer-term gut health improvement, adding kefir or fiber-boosted smoothies as a daily habit addresses the underlying causes rather than just the symptoms. Save senna tea and magnesium citrate for those stubborn episodes when the gentler approaches aren’t cutting it.