Several over-the-counter options can help you have a bowel movement, ranging from fiber supplements that work within a day or two to saline laxatives that can work in under an hour. The best choice depends on how quickly you need relief and whether this is an occasional problem or a recurring one.
Fiber Supplements: The Gentle First Option
Fiber supplements are the most commonly recommended starting point for constipation. Products containing psyllium (sold as Metamucil) or methylcellulose (Citrucel) absorb water in your intestines, swell up, and form a soft, bulky stool that’s easier to pass. They typically take 12 to 72 hours to produce a bowel movement, so they’re not the right pick if you need immediate relief.
Take fiber supplements with a full glass of water, and keep drinking fluids throughout the day. Fiber without enough water can actually make things worse by creating a dry, hard mass in your intestines. If you’re not used to much fiber, start with a small dose and increase gradually over a few days to avoid bloating and gas.
Osmotic Laxatives for Reliable Relief
Osmotic laxatives work by pulling water into your colon, which softens stool and triggers a bowel movement. The most popular option is polyethylene glycol 3350, sold as MiraLAX. It’s a powder you mix into any drink, and it has almost no taste. In clinical trials reviewed by the FDA, about 46% of people had a bowel movement on the first day, 63% by day two, and 80% by day three. Plan for two to four days before it fully kicks in.
Magnesium-based options work faster. Magnesium citrate, sold as a liquid in most pharmacies, acts as a saline laxative and can produce results in 30 minutes to three hours. It’s a stronger option best saved for when you really need it rather than daily use. Milk of Magnesia (magnesium hydroxide) falls somewhere in between, working within a few hours for most people.
Stool Softeners
Docusate (sold as Colace) is a stool softener that helps water and fat mix into hard stool, making it easier to pass. It’s one of the gentlest options available but also one of the least powerful. Stool softeners work best for preventing straining rather than breaking up a stubborn blockage. They’re often recommended after surgery or during pregnancy when you want to keep things moving without forcing anything.
Stimulant Laxatives: Fast but Not for Every Day
Stimulant laxatives like senna (found in Ex-Lax and Senokot) and bisacodyl (Dulcolax tablets) trigger contractions in your bowel muscles to physically push stool through. They’re effective and relatively fast, generally working within 6 to 12 hours when taken by mouth. Suppository versions of bisacodyl work even faster, typically within 15 to 60 minutes.
The tradeoff is that stimulant laxatives carry a real risk of dependency if used too often. Your bowel can stop functioning normally without them, creating a cycle where you need the laxative just to go. Use them for occasional relief, not as a daily habit.
Foods and Drinks That Help
Prune juice is one of the most effective natural remedies, and it works through three separate mechanisms. The fiber adds bulk to your stool. Sorbitol, a sugar alcohol naturally present in prunes, draws water into the bowel and produces softer stools. And polyphenols in prunes feed beneficial gut bacteria that support digestion. Whole prunes work even better than the juice because they contain more fiber.
Beyond prunes, increasing your overall fiber intake from food makes a measurable difference. Women should aim for 25 to 30 grams of fiber per day, and men should target 30 to 38 grams, according to Johns Hopkins Medicine. Most people fall well short of those numbers. Good sources include beans, lentils, oats, berries, broccoli, and whole grains. As with fiber supplements, water is essential to helping fiber do its job.
Coffee is another option many people already use instinctively. It stimulates contractions in the colon and can prompt a bowel movement within minutes for some people.
Probiotics for Ongoing Constipation
If constipation is a recurring problem for you, probiotics may help over time. Two strains have the strongest evidence. Bifidobacterium lactis has been shown to increase how often people have bowel movements. Lactobacillus casei Shirota (the strain in Yakult drinks) goes further, improving stool consistency and reducing pain, straining, and the feeling of incomplete emptying. These aren’t quick fixes. You’d need to take them consistently for several weeks to see results.
Choosing Based on How Quickly You Need Relief
- Within an hour: Bisacodyl suppository (15 to 60 minutes) or magnesium citrate liquid (30 minutes to 3 hours)
- Overnight: Senna or bisacodyl tablets taken before bed (6 to 12 hours)
- Within a few days: MiraLAX (2 to 4 days) or fiber supplements (12 to 72 hours)
- For ongoing prevention: Daily fiber from food or supplements, adequate water, and possibly probiotics
Signs Something More Serious Is Going On
Most constipation resolves with the options above. But if you haven’t had a bowel movement for an extended period and you’re also experiencing severe bloating or abdominal pain, that combination can signal a medical emergency like a bowel obstruction. Blood in your stool, vomiting during constipation, or unexplained weight loss alongside changes in your bowel habits are all reasons to get medical attention promptly rather than reaching for another laxative.