The best foods to eat when you’re constipated are those rich in fiber, natural sugar alcohols, or both. Prunes, kiwifruit, oatmeal, leafy greens, apples, and whole grains top the list. Most adults need 25 to 38 grams of fiber per day, and falling short of that target is one of the most common dietary causes of constipation.
Why Fiber Works (and Why the Type Matters)
Not all fiber helps constipation in the same way, and some forms can actually make things worse. There are two broad categories: soluble fiber and insoluble fiber. Soluble fiber dissolves in water and forms a gel that helps stool retain moisture as it moves through the colon, preventing it from drying out and becoming hard. Oatmeal, bananas, apples, cooked vegetables, and whole grains are good sources.
Insoluble fiber doesn’t dissolve in water. Instead, coarse particles of it gently irritate the lining of the large intestine, which triggers the intestinal wall to secrete water and mucus. That extra fluid softens stool and speeds things along. You’ll find insoluble fiber in the skins and seeds of fruits and vegetables, leafy greens, popcorn, nuts, and dried fruit.
One important detail: particle size matters for insoluble fiber. Coarse, chunky sources like whole wheat bran flakes have a genuine laxative effect, while finely ground wheat bran can actually be constipating because it adds bulk without triggering that water secretion. So when choosing bran cereals or whole grain products, coarser is better.
Some of the most effective foods deliver both types at once. Apples and potatoes, for instance, contain soluble fiber in their flesh and insoluble fiber in their skin. Eating the whole food, skin included, gives you the full benefit.
Prunes: The Gold Standard
Prunes have earned their reputation for a reason that goes beyond fiber. They’re rich in sorbitol, a naturally occurring sugar alcohol that draws water into the intestines, working like a mild osmotic laxative. This one-two punch of fiber plus sorbitol makes prunes more effective than many other high-fiber foods on their own.
Prune juice works too. In a clinical trial, participants who drank about one cup (200 grams) of prune juice daily reported fewer hard, lumpy stools after just three weeks. By seven weeks, most had regular bowel movements. If you don’t enjoy prunes, apple juice contains sorbitol as well, though in smaller amounts.
Kiwifruit for Daily Regularity
Green kiwifruit is one of the more underrated constipation remedies. Eating two peeled green kiwis per day has been shown to increase bowel movement frequency in people with mild constipation. The mechanism is unique: kiwifruit cell walls have an unusually strong ability to swell and hold onto water inside the colon, which keeps stool soft and easier to pass. Kiwis are also mild enough to work for people with irritable bowel syndrome who sometimes react poorly to high-fiber interventions.
More Foods That Help
Beyond prunes and kiwis, you have plenty of options to build meals around:
- Oatmeal: A reliable source of soluble fiber that forms a gel in the gut. A bowl at breakfast is one of the simplest daily habits for regularity.
- Leafy greens: Spinach, kale, and Swiss chard provide insoluble fiber along with magnesium, a mineral that helps muscles in the intestinal wall contract.
- Beans and lentils: Among the most fiber-dense foods available. A half cup of cooked lentils delivers around 8 grams of fiber.
- Whole grains: Brown rice, whole wheat bread (look for coarse-ground), barley, and quinoa all contribute meaningful soluble fiber.
- Dried fruit: Figs, apricots, and dates are concentrated sources of both fiber and natural sugars that help draw water into the colon.
- Nuts and seeds: Almonds, chia seeds, and flaxseeds add insoluble fiber. Chia seeds also absorb water and form a gel, which can soften stool.
- Popcorn: A surprisingly good source of insoluble fiber at about 3.5 grams per three-cup serving, as long as it’s not drowning in butter.
Fermented Foods and Gut Bacteria
Your gut bacteria play a role in how quickly food moves through your intestines, and fermented foods can shift that balance in a helpful direction. Yogurt, kefir, sauerkraut, and kimchi introduce beneficial bacteria that may improve gut transit time and stool consistency. The effects tend to be strain-specific. Certain strains of Bifidobacterium lactis, commonly found in probiotic yogurts and fermented milks, have shown the most consistent benefits for constipation in clinical studies.
Fermented foods aren’t a quick fix the way prunes can be, but incorporating them regularly may help prevent constipation from recurring, especially when paired with prebiotic fiber sources like oats, bananas, and garlic that feed those beneficial bacteria.
How to Add Fiber Without Making Things Worse
Jumping from a low-fiber diet to 38 grams a day overnight will likely cause bloating, gas, and cramping. Increase your intake gradually over one to two weeks, adding a few grams per day. Drink more water as you go. Fiber works by absorbing and holding water in the colon, so without enough fluid, adding fiber can actually make constipation worse.
The daily fiber target is 25 grams for women and 38 grams for men. Most Americans eat about 15 grams, so there’s a significant gap to close. A practical approach: add one new high-fiber food per meal. Oatmeal with chia seeds at breakfast, an apple with the skin at lunch, and a side of lentils or roasted vegetables at dinner can bring you close to the goal without overhauling your entire diet at once.
Foods That Can Make Constipation Worse
While you’re adding helpful foods, it’s worth cutting back on the ones working against you. Processed and low-fiber foods tend to slow things down: white bread, white rice, chips, fast food, and frozen meals made with refined grains. Dairy can be constipating for some people, particularly cheese and ice cream. Red meat is slow to digest and contains no fiber, so large portions without a fiber-rich side dish can contribute to the problem. Alcohol and excessive caffeine both dehydrate you, reducing the water available to soften stool.
You don’t need to eliminate these foods entirely. The goal is tilting the overall balance of your diet toward more whole, fiber-rich, water-retaining foods and away from heavily processed, low-fiber options.