Kratom typically does the opposite of making you poop. Like other substances that act on opioid receptors in the body, kratom slows down your digestive system and is far more likely to cause constipation than to stimulate a bowel movement. In a survey of nearly 2,900 U.S. adults who used kratom, about 5% reported constipation as a side effect. The one exception: if you stop taking kratom after regular use, diarrhea is a common withdrawal symptom.
How Kratom Slows Your Gut
The active compounds in kratom bind to the same receptors that opioid painkillers do, and that includes receptors lining your intestinal walls. When those receptors are activated, the muscles in your gut contract less frequently, which means food and waste move through your system more slowly. Water gets absorbed from stool for longer than usual, leaving it harder and more difficult to pass.
Animal research has demonstrated this clearly. In one study, kratom extract slowed intestinal transit in a dose-dependent way, meaning higher doses caused more pronounced effects. At lower doses, the slowdown was modest. At higher doses, gut motility dropped significantly compared to controls. This mirrors what happens with traditional opioids, which are notorious for causing constipation even at prescribed doses.
Why Dose Matters
Kratom’s effects on digestion shift depending on how much you take. At low doses (often described by users as 1 to 3 grams of dried leaf), kratom tends to act more as a stimulant, and digestive effects may be mild or unnoticeable. At higher doses (5 grams and above), the opioid-like effects dominate, and constipation becomes much more likely. People who use kratom daily or in large amounts report the most significant changes in bowel habits.
This dose relationship also showed up in rat studies, where higher doses of kratom extract not only slowed intestinal transit but also provided “protection” against induced diarrhea, essentially confirming that the substance acts as a gut-slowing agent at meaningful doses.
Withdrawal Flips the Script
If kratom generally causes constipation, stopping it after regular use often triggers the opposite problem. Diarrhea is one of the most commonly reported kratom withdrawal symptoms, alongside nausea, muscle aches, insomnia, and headaches. This happens because your gut has adapted to being slowed down. When the substance is removed, intestinal activity rebounds, sometimes aggressively.
Withdrawal symptoms typically last less than a week and tend to be more severe in people who used kratom heavily or for extended periods. The diarrhea during this phase can be uncomfortable but is generally self-limiting.
Effects on Gut Bacteria
Beyond motility, kratom may also change what’s living in your gut. A 2025 study in rats found that kratom extract significantly altered the composition of gut bacteria. Some beneficial bacterial groups increased, while others shifted in ways associated with less favorable health outcomes. Interestingly, overall bacterial diversity stayed roughly the same between treated and untreated animals, suggesting kratom reshuffles the microbial community rather than wiping it out.
What this means for human digestion long-term isn’t fully clear, but shifts in gut bacteria can influence everything from stool consistency to bloating and gas. It’s another layer of how kratom interacts with your digestive system beyond simply slowing things down.
Managing Kratom-Related Constipation
If you use kratom and find yourself struggling with constipation, a few practical strategies can help keep things moving:
- Increase fiber intake. Adding ground flaxseed (about 2 tablespoons daily) to food or smoothies adds bulk to stool and encourages movement through the intestines.
- Stay hydrated. Aim for 6 to 8 glasses of water a day. When your gut is already absorbing extra water from slowed transit, dehydration makes constipation significantly worse.
- Try magnesium citrate. Starting at around 200 mg daily and gradually increasing can soften stool effectively. If you develop loose stools, reduce the dose slightly.
- Move your body. Regular physical activity stimulates the muscles in your intestinal walls, counteracting some of the slowdown kratom causes.
- Consider healthy fats. MCT oil and similar fats can have a mild laxative effect that helps offset opioid-receptor-driven constipation.
The most direct fix, of course, is reducing your kratom dose. Since the constipation effect is dose-dependent, using less will generally mean less digestive disruption.
One Safety Note Worth Knowing
Kratom products have been linked to Salmonella contamination in the past. The FDA investigated a multistate outbreak tied to kratom products, and Salmonella infection causes its own gastrointestinal problems: diarrhea, fever, and abdominal cramps. If you experience sudden, severe diarrhea after taking kratom (especially a new batch), contamination is worth considering as a cause, particularly if you also develop a fever. In some cases, Salmonella infections require hospitalization.