Several over-the-counter options can relieve constipation, ranging from fast-acting stimulant laxatives that work in 6 to 12 hours to gentler alternatives like fiber supplements and osmotic laxatives that work within one to three days. The best choice depends on how quickly you need relief and whether this is an occasional problem or a recurring one.
Fast Relief: Stimulant Laxatives
If you need to go soon, stimulant laxatives are the quickest oral option. Products containing bisacodyl or senna work by triggering contractions in the colon and increasing fluid secretion into the intestines. Most people get results within 6 to 12 hours, which is why taking one before bed often produces a morning bowel movement.
These are effective for occasional use, but they’re not meant to be a daily habit. Using stimulant laxatives regularly can make your bowel dependent on them, so treat them as a short-term fix rather than a routine.
Gentle and Consistent: Osmotic Laxatives
Polyethylene glycol 3350 (sold as MiraLAX and store-brand equivalents) is one of the most commonly recommended options for constipation that isn’t urgent. It works by drawing water into the intestines, which softens stool and makes it easier to pass. The standard dose is about one heaping tablespoon mixed into any beverage, taken once daily for up to two weeks.
Osmotic laxatives are slower than stimulants. You may not notice results for one to three days. But they’re gentler, produce less cramping, and are generally well tolerated for short stretches. Magnesium citrate is another osmotic option that tends to work faster, often within a few hours. It comes as a liquid and is sometimes used for more stubborn constipation. Magnesium oxide tablets can also help, though they’re less potent as a laxative.
Fiber Supplements
Bulk-forming fiber supplements like psyllium (Metamucil), methylcellulose (Citrucel), and calcium polycarbophil (FiberCon) absorb water in the intestines, making stool bulkier, softer, and easier to pass. They’re the closest thing to a natural, everyday solution you can buy at a pharmacy.
The tradeoff is patience. Fiber supplements can take two to three days to produce noticeable improvement, and they work best when you take them consistently rather than as a one-time rescue. One critical detail: you need to drink at least 48 ounces of water daily when using fiber supplements. Without enough fluid, the extra fiber can actually make things worse by creating a dry, bulky mass that’s harder to move.
Foods That Help You Go
Prunes are the classic recommendation, and they genuinely work. A randomized trial published in the American Journal of Gastroenterology found that about 12 prunes daily provided meaningful relief for people with chronic constipation, delivering both fiber and a natural sugar alcohol called sorbitol that draws water into the colon.
Green kiwifruit is a surprisingly effective alternative. In the same trial, two peeled kiwifruits daily improved both constipation and bloating. Both the prunes and kiwifruits delivered roughly equivalent fiber, but kiwi also contains an enzyme that may help with digestion beyond its fiber content alone. Other reliable options include pears, figs, flaxseed, and oatmeal.
Coffee Works, and It’s Not the Caffeine
If you’ve noticed that your morning coffee sends you to the bathroom, that’s not a coincidence. Coffee triggers strong contractions in the smooth muscle of the colon by activating receptors in both the gut’s nerve cells and the muscle tissue itself. What’s interesting is that decaffeinated coffee produces virtually the same effect. The compounds responsible for stimulating the gut aren’t caffeine but other molecules in the coffee that act on the same receptor pathways. So if you’re sensitive to caffeine but want the bowel-stimulating benefit, decaf is a legitimate option.
Probiotics for Ongoing Sluggishness
Probiotics won’t rescue you from acute constipation, but if your gut is consistently slow, they may help over time. A meta-analysis of randomized controlled trials found that probiotic supplementation reduced whole gut transit time by nearly 14 hours on average. Among the strains studied, Bifidobacterium lactis showed the strongest benefit for stool frequency and transit speed. You can find this strain in many commercial probiotic supplements and some yogurts. Expect to take them for several weeks before noticing a difference.
How Much Fiber You Actually Need
Most constipation is partly a fiber problem. The federal Dietary Guidelines recommend 25 to 28 grams of fiber daily for adult women and 31 to 34 grams for adult men, depending on age. The reality is that more than 90 percent of women and 97 percent of men fall short of these targets. Closing that gap through food, supplements, or both is the single most effective long-term strategy for staying regular.
If you’re currently eating very little fiber, increase your intake gradually over a week or two. A sudden jump can cause gas, bloating, and cramping. Pair any increase with extra water, aiming for 48 to 64 ounces daily.
Signs That Need Medical Attention
Occasional constipation is common and usually harmless. But certain symptoms point to something that needs evaluation rather than an over-the-counter fix:
- Constipation lasting longer than three weeks
- Rectal bleeding or blood on toilet tissue
- Black stools or blood visible in your stool
- Unusual changes in the shape or color of your stool
- Stomach pain that doesn’t go away
- Symptoms severe enough to interfere with daily activities
Chronic constipation, defined as experiencing two or more of these patterns for three months or longer, is worth discussing with a healthcare provider to rule out underlying causes.