Several over-the-counter options can relieve constipation, ranging from fiber supplements that work within a day or two to stimulant laxatives that can produce a bowel movement in under an hour. The right choice depends on how quickly you need relief and whether you’re dealing with a one-time issue or an ongoing pattern.
Fiber Supplements
Fiber supplements are the gentlest starting point. Products containing psyllium husk or methylcellulose work by absorbing water in your gut, which bulks up your stool and makes it easier to pass. They typically take one to three days to kick in, so they’re not the answer if you need relief tonight. But for mild or recurring constipation, they’re often the first thing worth trying.
The general recommendation for dietary fiber is about 14 grams per 1,000 calories you eat, which works out to roughly 25 grams a day for most women and 30 to 35 grams for most men. Most Americans fall well short of that. If you’re adding a fiber supplement, start with a small dose and increase gradually. Too much fiber too fast, especially without enough water, can actually make bloating and constipation worse.
Osmotic Laxatives
Osmotic laxatives like polyethylene glycol 3350 (sold as MiraLAX and generics) work by pulling water into your intestines. That extra water softens the stool and increases the number of bowel movements. They’re available without a prescription and are widely used for occasional and chronic constipation alike. Most people see results within one to three days. You dissolve the powder in a drink and take it once daily.
Magnesium citrate is another osmotic option that tends to work faster, sometimes within a few hours. It’s sold as a liquid at most pharmacies. Because it pulls a significant amount of water into the colon, it can cause cramping and loose stools, and it shouldn’t be used for more than one week at a time. People with kidney disease or those on a magnesium-restricted diet should avoid it without medical guidance, since excess magnesium can throw off your electrolyte balance.
Stimulant Laxatives
When you need results quickly, stimulant laxatives are the most reliable option. Products containing bisacodyl or senna work by triggering rhythmic muscle contractions in your large intestine, physically pushing stool through. Taken by mouth, they typically produce a bowel movement within 6 to 12 hours. Bisacodyl is also available as a rectal suppository, which works much faster: 15 to 60 minutes in most cases.
Stimulant laxatives are effective but not meant for daily long-term use. Your body can become dependent on them for normal bowel function if you rely on them regularly. They’re best suited for occasional constipation or situations where gentler options haven’t worked after a few days.
Stool Softeners Are Less Effective Than You’d Think
Stool softeners containing docusate sodium are one of the most commonly recommended constipation remedies, but the evidence behind them is surprisingly weak. A randomized, double-blind trial published in the Journal of Pain and Symptom Management compared docusate plus a stimulant laxative against a placebo plus the same stimulant laxative. The result: no significant difference in stool frequency, volume, consistency, or ease of passing. The docusate added essentially nothing.
That doesn’t mean stool softeners are harmful. They’re just unlikely to be the thing that actually gets you going. If you’re choosing between a stool softener and an osmotic or stimulant laxative, the latter two have stronger evidence behind them.
Food and Drinks That Help
Before reaching for a pharmacy product, a few dietary changes can make a real difference. Prunes are the classic home remedy for good reason: they contain both fiber and sorbitol, a natural sugar alcohol that draws water into the intestines much like an osmotic laxative. Five to six prunes a day is a reasonable starting amount.
Coffee is another reliable option for many people. Compounds in coffee, particularly one called furan, stimulate the release of a hormone called gastrin from the stomach lining. Gastrin increases gut motility, essentially speeding up the muscular contractions that move things through your digestive tract. This effect happens even with decaf coffee, since it’s driven by the coffee itself rather than caffeine alone. For some people, a cup of coffee in the morning is all it takes.
Water matters too, especially if you’re increasing your fiber intake. Fiber works by absorbing water, so if you’re not drinking enough fluids, adding more fiber can backfire. There’s no magic number, but aiming for six to eight glasses a day is a reasonable baseline when you’re trying to get things moving.
Choosing the Right Option by Timeline
- Within the hour: A bisacodyl suppository (15 to 60 minutes) is the fastest over-the-counter option.
- By tomorrow morning: An oral stimulant laxative taken at bedtime (6 to 12 hours) or magnesium citrate liquid (a few hours).
- Within a few days: An osmotic laxative like polyethylene glycol 3350 or a fiber supplement (1 to 3 days).
- Ongoing prevention: Increasing dietary fiber through food and supplements, staying hydrated, and regular physical activity.
Signs Something More Serious Is Going On
Occasional constipation is extremely common and usually nothing to worry about. But constipation paired with certain other symptoms can signal an underlying problem that needs evaluation. Rectal bleeding, unexplained weight loss, persistent abdominal pain, fever, nausea, or vomiting alongside constipation are all red flags. The same goes for a sudden, significant change in your bowel habits that doesn’t improve with basic remedies, especially if you’re over 50. In those cases, the issue isn’t just “what can I take” but rather what’s causing the constipation in the first place.