Most constipation responds well to a combination of dietary changes, more fluids, physical activity, and, when needed, over-the-counter laxatives. Fewer than three bowel movements per week, hard or lumpy stools, and frequent straining are the hallmarks. For the majority of people, the fix starts with what you eat and drink, not with medication.
Start With Fiber
Fiber is the single most important dietary change you can make. Current guidelines recommend 14 grams of fiber for every 1,000 calories you eat per day, which works out to roughly 25 to 35 grams for most adults. The average American gets about half that. A joint guideline from the American College of Gastroenterology and the American Gastroenterological Association lists fiber supplements as a first-line therapy, particularly for people whose intake is low.
Not all fiber works the same way. Insoluble fiber, found in whole wheat flour, wheat bran, nuts, beans, cauliflower, green beans, and potatoes, adds bulk to stool and helps push material through the digestive tract. This is the type most directly useful for constipation. Soluble fiber, found in oats, apples, bananas, avocados, citrus fruits, carrots, barley, and psyllium, dissolves in water and forms a gel that slows digestion. It has other benefits (cholesterol, blood sugar), but for constipation specifically, you want plenty of the insoluble kind.
If your current fiber intake is low, increase it gradually over a week or two. Adding too much too fast causes bloating and gas, which discourages people from sticking with it. Pair any increase in fiber with extra water.
Drink More Fluids
Water matters more than many people realize. A large analysis of U.S. adults found that people in the highest quarter of daily fluid intake had roughly half the constipation risk of those in the lowest quarter. That lowest group was drinking under about 1.9 liters (roughly 8 cups) per day; the highest group was above 3.4 liters. The relationship was dose-dependent, meaning more fluid correlated with progressively lower risk.
One clinical trial found that combining a high-fiber diet with 2 liters of water daily significantly increased bowel movement frequency and reduced the need for laxatives. The takeaway: if you’re boosting fiber, you need to boost water intake at the same time. Fiber absorbs water to do its job. Without enough fluid, extra fiber can actually make things worse.
Move Your Body
Physical activity speeds up the time it takes food to travel through your colon. Research tracking movement levels and gut transit found that for every additional hour spent doing light-to-moderate activity (think brisk walking, not intense exercise), colonic transit time was about 25% faster, independent of age, sex, or body fat. Interestingly, higher-intensity exercise didn’t show the same clear association, so you don’t need to train hard. A daily 30- to 60-minute walk can make a real difference.
Change Your Sitting Position
The angle of your body on the toilet matters more than most people think. When you sit on a standard toilet, the muscle that wraps around your rectum (the puborectalis) keeps the passage at a roughly 80- to 90-degree angle, which partially pinches it off. Squatting opens that angle to about 100 to 110 degrees, straightening the rectum and making elimination easier.
You don’t need to squat on the floor. A simple footstool placed in front of your toilet, raising your knees above your hips, mimics the effect. In one study, using a footstool cut average defecation time roughly in half (about 56 seconds versus 113 seconds) and participants reported noticeably less straining. Leaning your upper body forward while using the stool helps even more, particularly for older adults.
Over-the-Counter Laxatives
When lifestyle changes aren’t enough, laxatives are the next step. They come in three main categories, and it helps to understand the differences so you pick the right one.
- Bulk-forming laxatives (psyllium, methylcellulose) work like supplemental fiber. They hold water in the stool, making it softer and heavier. These are the gentlest option and safe for daily use. They take one to three days to work.
- Osmotic laxatives (polyethylene glycol, milk of magnesia, lactulose) draw water into the bowel from surrounding tissue. They typically produce a bowel movement within one to three days. Polyethylene glycol, combined with a stimulant like bisacodyl, received the strongest recommendation in the 2024 ACG/AGA guideline for chronic constipation.
- Stimulant laxatives (bisacodyl, senna) trigger the muscles in your intestinal wall to contract more forcefully while also reducing water absorption. These work faster, often within 6 to 12 hours, and are useful for short-term relief. They’re not ideal for daily long-term use.
For occasional constipation, any of these is reasonable. For ongoing problems, start with bulk-forming or osmotic laxatives, which have better safety profiles for extended use.
Magnesium Supplements
Magnesium citrate works as an osmotic laxative, pulling water into the intestines. The ACG/AGA guideline gives magnesium oxide a conditional recommendation for chronic constipation. It’s widely available, inexpensive, and effective for many people. However, it’s intended for occasional use. Prolonged daily use can cause electrolyte imbalances, particularly in people with kidney problems. If you find yourself relying on it regularly, that’s a sign to look at other options or talk to a healthcare provider.
Probiotics for Constipation
Probiotics can help, but the strain matters enormously. A meta-analysis in the World Journal of Gastroenterology found that two specific strains of Bifidobacterium lactis (HN019 and DN-173 010) produced meaningful reductions in gut transit time, while other probiotic strains had small, statistically insignificant effects. The benefit was also notably larger in people who already had constipation compared to those with normal bowel function.
This means grabbing a random probiotic off the shelf is unlikely to help. If you want to try this route, look for products that specifically contain B. lactis HN019 or DN-173 010. The latter is the strain found in certain Activia yogurt products.
Warning Signs That Need Attention
Most constipation is functional, meaning nothing structurally wrong is causing it. But certain symptoms alongside constipation warrant a medical evaluation: blood in or on your stool, unexplained weight loss, abdominal pain or cramps that persist, or a new and lasting change in bowel habits, especially after age 45. These can overlap with symptoms of colorectal conditions that benefit from early detection. A sudden onset of constipation that doesn’t respond to any of the above measures, particularly in someone who previously had regular bowel habits, also deserves investigation.
Chronic constipation, formally defined as symptoms present for at least three months, sometimes involves pelvic floor dysfunction where the muscles involved in elimination don’t coordinate properly. This won’t respond to fiber or laxatives. It’s treated with a specific form of physical therapy called biofeedback training, which has strong success rates. If you’ve tried everything above for several weeks without improvement, pelvic floor dysfunction is worth discussing with a gastroenterologist.