The fastest way to trigger a bowel movement is with a rectal suppository or enema, which can work in as little as 15 minutes. If you’d rather avoid those, a cup of coffee, physical movement, or an over-the-counter osmotic laxative can also speed things along, though each works on a different timeline. Here’s what actually works, ranked roughly by how quickly you can expect results.
Enemas and Suppositories: Minutes
If you need to go right now, rectal options are the fastest. Cleansing enemas (saline or tap water) work within minutes by physically softening and flushing stool from the lower colon. Most people have a bowel movement within 15 minutes of an enema, though some types take up to an hour to fully clear things out.
Glycerin suppositories and stimulant suppositories (bisacodyl) are the next fastest. Bisacodyl suppositories typically produce a bowel movement within 15 to 60 minutes by triggering contractions in the rectal wall. Glycerin works on a similar timeline by drawing water into the stool and lubricating the passage. Both are available over the counter at any pharmacy. Insert the suppository, lie on your side for a few minutes, and wait for the urge.
Coffee: 4 to 30 Minutes
Coffee stimulates the colon with surprising speed. Research published in the Scandinavian Journal of Gastroenterology found that coffee increases muscle activity in the lower colon within four minutes of drinking it. The effect is comparable to eating a 1,000-calorie meal, even though coffee has essentially no calories. Scientists believe something beyond caffeine is responsible, since decaf coffee also triggers the response in many people, though the exact compounds aren’t fully identified.
Not everyone gets this effect, but if you’re one of the people whose gut responds to coffee, a warm cup on an empty stomach is one of the simplest ways to get things moving quickly. Drinking it with breakfast amplifies the signal, since eating also triggers the gastrocolic reflex, your body’s natural urge to make room after a meal.
Change Your Position on the Toilet
If you’re sitting on the toilet and struggling, adjusting your posture can make a real difference. When you sit upright on a standard toilet, the muscle that wraps around your rectum (the puborectalis) creates a natural bend that partially pinches the passage shut. Raising your feet on a small stool or a stack of books so your knees are above your hips straightens that bend. In studies comparing squatting to sitting, people who squatted needed less time and less straining to reach what researchers call a “sensation of satisfactory bowel emptying.”
You don’t need a branded squatting stool. Anything that raises your feet six to nine inches works. Lean forward slightly, relax your belly, and let gravity help rather than pushing hard.
Osmotic Laxatives: 30 Minutes to 3 Hours
Magnesium citrate is the classic “drink this bottle and clear out” option sold at pharmacies. It works by pulling water into the intestines through osmosis, which softens the stool and triggers stronger contractions in the colon. Saline-type laxatives like this generally take 30 minutes to three hours to produce a bowel movement. Drink it with a full glass of water and stay near a bathroom.
Magnesium citrate is meant for occasional, short-term use. It’s effective but can cause cramping, and it pulls fluid from your body, so drink extra water to avoid dehydration. People with kidney problems should avoid it, since the kidneys are responsible for clearing excess magnesium.
Warm Water and Movement
Drinking a large glass of warm water first thing in the morning can activate the gastrocolic reflex, the same wave of contractions that coffee and food trigger. It won’t work as dramatically as coffee for most people, but it’s a zero-risk starting point, especially if you’re mildly backed up rather than severely constipated.
Physical movement helps too. Walking, light jogging, or even gentle twisting stretches increase blood flow to the intestines and physically jostle stool through the colon. A 10 to 15 minute walk after drinking something warm is a combination that works for many people without any products at all.
Prunes and High-Fiber Foods: Hours to Days
Prunes (dried plums) are one of the most studied natural remedies for constipation. In a randomized trial published in the American Journal of Gastroenterology, eating about 100 grams of prunes daily (roughly 10 to 12 prunes) significantly increased the number of complete bowel movements per week compared to baseline. They performed as well as psyllium husk fiber supplements when both provided the same amount of fiber. Prunes contain sorbitol, a natural sugar alcohol that draws water into the intestines, plus fiber that adds bulk.
Fiber-rich foods won’t help in the next 20 minutes, but they can get things moving within the same day. Soluble fiber (found in oats, prunes, apples, and beans) dissolves in water and forms a gel that softens stool, making it easier to pass. Insoluble fiber (found in whole wheat, vegetables, and bran) acts as roughage, adding bulk that pushes stool through faster. Both types help, but you need to drink plenty of water alongside them. Adding a lot of fiber without enough water can actually make constipation worse and cause bloating, gas, or cramping, especially if your usual diet is low in fiber.
What to Watch For
Occasional constipation is common and usually harmless. But if you haven’t had a bowel movement for an extended period and you’re also experiencing severe abdominal pain or major bloating, that combination can signal something more serious, like a bowel obstruction. Vomiting alongside constipation, blood in your stool, or unexplained weight loss are also signs that warrant prompt medical attention rather than home remedies.
For run-of-the-mill constipation, start with the fastest option you’re comfortable with. Coffee and a squatting position cost nothing and work within minutes for many people. If those don’t do the job, a glycerin suppository or magnesium citrate from the pharmacy will handle most situations the same day.