The fastest way to relieve constipation is with a bisacodyl suppository, which can produce a bowel movement in as little as 15 minutes. If you prefer something you can swallow, magnesium citrate liquid typically works within 30 minutes to 6 hours. Beyond those options, several other strategies can get things moving within hours or days depending on what you have on hand and how long you’ve been backed up.
Options That Work Within Hours
If you need relief today, these are your fastest bets, ranked roughly by how quickly they tend to act.
Bisacodyl suppositories are the quickest over-the-counter option. Inserted rectally, they stimulate the muscles of the lower bowel directly and produce a movement in 15 to 60 minutes for most people. They’re widely available at any pharmacy without a prescription.
Magnesium citrate liquid is an oral solution that pulls water into your intestines, softening stool and triggering contractions. It usually works within 30 minutes to 6 hours. The taste is tart and salty, so drinking it chilled helps. This is a strong osmotic laxative, so stay near a bathroom once you take it.
Bisacodyl tablets and senna tablets are stimulant laxatives taken by mouth. Both generally take 6 to 12 hours to work. If you take them before bed, you can expect a bowel movement by morning. Senna is also sold as a tea, which some people find easier to tolerate.
Simple Things You Can Do Right Now
While you wait for a laxative to kick in, or if you’d rather try non-medication approaches first, a few physical strategies can help move things along.
Drinking warm water or coffee first thing in the morning stimulates what’s called the gastrocolic reflex, a natural wave of contractions that pushes contents through the colon. Coffee is especially effective because it increases motility in the large intestine within minutes of drinking it. A glass of warm water with a meal can have a milder version of the same effect.
Abdominal massage is surprisingly well supported. A meta-analysis of clinical trials found that massaging the abdomen reduced gut transit time by an average of about 21 hours. The technique is simple: use your fingertips to apply gentle, firm pressure in a clockwise direction around the belly button, following the natural path of the colon. Spend about 10 to 15 minutes on it. Acupressure-style massage (pressing into specific points along the path) appears to be even more effective than simple circular rubbing.
Body position matters too. Sitting on the toilet with your knees raised above your hips straightens the angle of the rectum and makes it easier to pass stool. A small footstool in front of the toilet accomplishes this. Leaning forward slightly and bracing your elbows on your knees can add helpful pressure.
Foods and Drinks That Act as Natural Laxatives
Prune juice is the classic home remedy, and it works for a straightforward reason: prunes are rich in sorbitol, a sugar alcohol your body doesn’t fully absorb. Unabsorbed sorbitol draws water into the intestines, softening stool in a way similar to osmotic laxatives. In clinical testing, drinking about 250 mL (roughly one cup) of prune juice per day, split into two servings, produced a measurable laxative effect. Results aren’t as fast as a stimulant laxative, but many people notice improvement within 12 to 24 hours.
Kiwifruit, figs, and flaxseed also have natural laxative properties due to their fiber content and, in the case of kiwi, an enzyme that improves gut motility. Two kiwis a day is a common recommendation that has shown results in studies of people with sluggish digestion.
Slower Options for Ongoing Relief
If constipation is something you deal with regularly, the strategies above will help in the short term, but a few longer-term changes can prevent it from coming back.
Polyethylene glycol 3350 (sold as MiraLAX and similar brands) is a gentle osmotic laxative that retains water in the stool. It’s effective and well tolerated, but it’s not fast. Expect 2 to 4 days before it produces a bowel movement. It works best as a daily maintenance option rather than a quick fix.
Fiber intake is the foundation of long-term regularity. Current dietary guidelines recommend about 14 grams of fiber per 1,000 calories you eat, which works out to roughly 25 to 30 grams per day for most adults. If you’re nowhere near that number, increase gradually. Adding too much fiber too fast can cause bloating and gas, which makes you feel worse before you feel better.
Here’s a detail most people miss: fiber needs water to work. A clinical study found that eating 25 grams of fiber daily improved stool frequency, but the effect was significantly stronger when participants also drank 1.5 to 2 liters of water per day. If you’re increasing fiber without increasing fluids, you may end up more constipated, not less.
Probiotics can also help, though they take weeks to show results. A strain called Bifidobacterium lactis HN019 improved bowel movement frequency in adults who were having fewer than three movements per week. The effect was modest, and probiotics won’t solve an acute episode, but they may reduce how often constipation returns.
Quick-Reference Comparison
- Bisacodyl suppository: 15 to 60 minutes
- Magnesium citrate liquid: 30 minutes to 6 hours
- Coffee or warm water: minutes to a few hours (mild effect)
- Bisacodyl or senna tablets: 6 to 12 hours
- Prune juice: 12 to 24 hours
- Polyethylene glycol (MiraLAX): 2 to 4 days
- Fiber and hydration changes: several days to a week
Signs That Constipation Needs Medical Attention
Most constipation resolves with the approaches above. But certain symptoms suggest something more serious, like a bowel obstruction, which requires immediate care. Get medical help if you have severe abdominal pain that comes and goes in waves, vomiting along with constipation, a visibly swollen or distended abdomen, or a complete inability to pass gas. That last one is key: if you can’t pass gas at all, that’s different from ordinary constipation and can signal a blockage that won’t respond to laxatives.