Do All Painkillers Give You Constipation? Separating Fact from Fiction

October 10, 2025 •

4 min read

Up to 81% of chronic opioid users experience opioid-induced constipation (OIC), a side effect that is both common and persistent. This startling statistic leads many to wonder, do all painkillers give you constipation? However, the answer is no; the risk varies dramatically based on the type of medication you are taking.

Quick Summary

Constipation risk varies widely among painkillers, with opioids being the most common cause. Other types, like NSAIDs and acetaminophen, are far less likely to cause this side effect.

Key Points

Opioids are the primary cause of painkiller constipation: Strong prescription opioids like morphine, oxycodone, and fentanyl commonly cause significant constipation by slowing down intestinal movement.
Non-opioid painkillers have a low constipation risk: Over-the-counter NSAIDs (ibuprofen) and acetaminophen (Tylenol) are much less likely to cause constipation, especially at recommended doses.
The mechanism of constipation varies by drug class: Opioids directly affect gut receptors to slow motility, while NSAIDs might cause digestive upset through gut irritation.
Constipation risk increases with higher doses and chronic use: Even for lower-risk drugs like NSAIDs, persistent or high-dose use increases the likelihood of digestive issues, including constipation.
Effective management strategies are available: Treatment for painkiller-related constipation can range from lifestyle changes and OTC laxatives to specialized prescription medications (PAMORAs) for severe, opioid-induced cases.
Tolerance to opioid side effects does not include constipation: While patients may develop a tolerance to other opioid side effects like drowsiness, OIC often persists as long as the medication is taken.
Communication with a healthcare provider is essential: Discussing bowel function with a doctor or pharmacist is crucial for anticipating and managing constipation, particularly when starting opioid therapy.

Understanding the Difference: Opioids vs. Non-Opioids

To understand the link between painkillers and constipation, it's crucial to distinguish between the primary types of pain medications. Broadly, painkillers fall into two main categories: opioids and non-opioid analgesics, which include Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and acetaminophen. The way these different drug classes interact with the body, particularly the digestive system, is the key factor determining their effect on bowel function.

The Primary Culprit: Opioid-Induced Constipation

Opioids are a class of strong pain medications prescribed for moderate to severe pain. Examples include morphine, hydrocodone, oxycodone, and fentanyl. The reason opioids are so effective at causing constipation is directly related to their mechanism of action. Opioids work by binding to opioid receptors, not just in the brain to relieve pain, but also in the gastrointestinal (GI) tract.

When opioids bind to the mu-opioid receptors in the gut, they trigger a series of physiological changes that result in constipation. These changes include:

Reduced Motility: Opioids inhibit the coordinated, wave-like contractions (peristalsis) of the intestinal muscles that move stool along the digestive tract.
Increased Water Absorption: The slowed transit time allows the bowel to absorb more water from the stool, making it harder, drier, and more difficult to pass.
Increased Sphincter Tone: Opioids can increase the tone of the anal sphincter, impairing the reflex that allows for defecation.

Unlike other opioid side effects like drowsiness, the body typically does not develop a tolerance to opioid-induced constipation (OIC), meaning it can be a persistent and ongoing problem for patients on long-term opioid therapy. Some opioids, like tramadol or fentanyl patches, may cause less constipation than others, but the risk remains significant.

The Low-Risk Medications: NSAIDs and Acetaminophen

For mild to moderate pain, many people turn to over-the-counter (OTC) painkillers like NSAIDs (e.g., ibuprofen, naproxen) and acetaminophen (e.g., Tylenol). The risk of these drugs causing constipation is significantly lower than with opioids.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): While commonly known for causing other GI side effects like stomach irritation, ulcers, or bleeding, constipation is a less frequent adverse effect. When it does occur, it is more likely with high doses or chronic use. The mechanism is thought to involve irritation of the gut lining, which can slow digestion.
Acetaminophen: Constipation is a very rare side effect of acetaminophen. While some studies have noted a potential association, especially with frequent, high-dose use over time, the risk is minimal for most users. Other GI issues like nausea and vomiting are more commonly reported. For individuals concerned about constipation, acetaminophen is generally considered a safer option than opioids from a digestive health perspective.

Managing Constipation from Painkillers

If you find yourself struggling with painkiller-related constipation, several strategies can help manage the symptoms. It is always important to consult a healthcare provider before starting or changing any treatment, especially for OIC.

Treatment Options for Painkiller Constipation

Lifestyle Adjustments: These should be the first line of defense. Increasing fluid intake, eating a diet rich in fiber (fruits, vegetables, whole grains), and engaging in regular physical activity can all help encourage regular bowel movements. However, lifestyle changes alone are often not sufficient for OIC.
Over-the-Counter (OTC) Laxatives: Various OTC options can be effective, particularly for constipation caused by NSAIDs or acetaminophen. Stimulant laxatives like senna or bisacodyl work by stimulating intestinal movement, while stool softeners like docusate sodium increase the water content of the stool. Osmotic laxatives, such as polyethylene glycol (MiraLAX) or magnesium hydroxide (Milk of Magnesia), draw water into the intestines.
Prescription Medications: For OIC that doesn't respond to traditional laxatives, healthcare providers may prescribe specialized medications called Peripherally Acting Mu-Opioid Receptor Antagonists (PAMORAs), such as methylnaltrexone (Relistor), naloxegol (Movantik), or naldemedine (Symproic). These drugs block the constipating effects of opioids in the gut without impacting pain relief in the central nervous system.

Comparing Common Painkillers and Constipation Risk

This table provides a quick overview of how different painkiller classes compare regarding their risk of causing constipation.


Painkiller Class	Examples	Constipation Risk	Mechanism of Action	Management Strategy
Opioids	Morphine, Oxycodone, Fentanyl, Hydrocodone	High. Common, persistent side effect	Binds to mu-opioid receptors in the gut, slowing motility and increasing water absorption.	Lifestyle adjustments, OTC laxatives, Prescription PAMORAs for refractory cases.
NSAIDs	Ibuprofen (Advil), Naproxen (Aleve)	Low to Moderate. Less common than opioids, especially with short-term use.	Can irritate the gut lining, slowing digestion, especially at high doses.	Lifestyle adjustments, OTC laxatives, especially with chronic use.
Acetaminophen	Tylenol	Very Low. Rare, though possible with chronic, high-dose use.	The mechanism is not fully understood, but its risk is minimal compared to opioids.	Typically not required, but lifestyle measures can help if symptoms occur.

Conclusion: Not All Painkillers Give You Constipation

In conclusion, the simple answer to the question "Do all painkillers give you constipation?" is no. The risk is overwhelmingly associated with opioid medications, which have a specific physiological effect on the digestive system. Non-opioid pain relievers like NSAIDs and acetaminophen are much less likely to cause this side effect. Understanding these differences allows for a more informed approach to pain management, helping individuals anticipate and effectively manage potential side effects. Always consult with a healthcare professional to determine the best course of action for your specific needs and medical history.

For more in-depth information on the differences between opioid and non-opioid medications, consider visiting the Centers for Disease Control and Prevention's non-opioid therapies page.

Frequently Asked Questions

Opioid painkillers are by far the most likely to cause constipation, a condition known as opioid-induced constipation (OIC). This is because they bind to receptors in the digestive system, slowing down bowel movements.

Yes, NSAIDs like ibuprofen and naproxen can cause constipation, but it is a much less common side effect than with opioids. The risk is higher with long-term, high-dose use.

Constipation is a very rare side effect of acetaminophen. While not impossible, the risk is minimal for most people taking standard doses and is much lower than with opioids or NSAIDs.

To prevent opioid-induced constipation, a healthcare provider will often recommend starting a laxative regimen at the same time as opioid therapy. Lifestyle changes like increased fluids, fiber, and exercise are also important.

Yes. For severe opioid-induced constipation that does not respond to standard laxatives, doctors may prescribe specific medications called Peripherally Acting Mu-Opioid Receptor Antagonists (PAMORAs), such as Relistor.

Non-opioid painkillers like NSAIDs and acetaminophen do not target the mu-opioid receptors in the gut. While they can cause other digestive issues, their effect on bowel motility is not as direct or significant.

For individuals on chronic opioid therapy, a consistent laxative regimen is often recommended to prevent constipation. You should discuss the appropriate preventative approach with your doctor or pharmacist.