Constipation from Opioids: Causes, Relief, and What to Do

When you take opioids, a class of powerful painkillers that include oxycodone, hydrocodone, morphine, and fentanyl. Also known as narcotics, they bind to receptors in your brain and spinal cord to block pain signals—but they also slow down your digestive system, leading to constipation from opioids. This isn’t just an inconvenience. It’s one of the most common, persistent, and under-treated side effects of long-term opioid use. Studies show up to 90% of people on chronic opioid therapy develop this issue, and many don’t tell their doctor because they think it’s just part of the deal.

Here’s why it happens: opioids don’t just affect your brain. They hit receptors in your gut too, reducing the natural muscle contractions that push food through your intestines. Your stomach empties slower, your intestines absorb more water from stool, and your rectum becomes less sensitive to the need to go. The result? Hard, dry stools, infrequent bowel movements, bloating, and sometimes painful straining. Over time, this can lead to hemorrhoids, rectal prolapse, or even bowel obstruction. And unlike nausea or drowsiness, which often fade after a few days, opioid-induced constipation doesn’t go away on its own. It gets worse with time.

What helps? Not just fiber or water—though those matter. Most over-the-counter laxatives like senna or magnesium citrate offer only temporary relief and can become less effective. The real solution is often a class of drugs called peripheral opioid antagonists, medications like methylnaltrexone or naloxegol that block opioid effects in the gut without touching pain relief in the brain. These are designed specifically for this problem. Some people also benefit from stool softeners, daily movement, and timed bathroom routines. But here’s the catch: many doctors still don’t screen for it. If you’re on opioids and haven’t talked about bowel habits in the last three months, you’re not getting full care.

This page pulls together real, practical advice from posts that cover how to manage this issue without quitting your pain meds. You’ll find what works, what doesn’t, and how to talk to your provider about it—without sounding like you’re complaining. You’ll also see how other medications, like those for depression or high blood pressure, can make it worse. And you’ll learn what to do when laxatives stop working, how to avoid dangerous interactions, and when it’s time to push for a different pain strategy.