Does Gabapentin Cause Constipation? What You Should Know

People who use gabapentin often wonder if the drug leads to constipation. This medication has caused bowel habit changes in many patients who just started taking it. The knowledge of gabapentin side effects on bowel movements, along with their occurrence rate and available treatment options, can enable you to handle your health and prescriptions effectively.

At Epiphany Wellness in Blackwood, New Jersey, we understand that navigating medication side effects can be frustrating. This article explores whether gabapentin causes constipation [1] and provides practical guidance for managing this potential effect.

Can Gabapentin Cause Constipation as a Side Effect?

Gabapentin is an anticonvulsant and neuropathic pain (chronic pain related to damaged or dysfunctional nerves, tissues, brain, or spinal cord) medication originally developed to treat seizures and epilepsy. It’s the generic form of the brand-name drug Neurontin. Healthcare providers prescribe gabapentin for nerve pain from diabetes, postherpetic neuralgia, shingles, restless legs syndrome, and chronic pain.

This medication can cause constipation, though this is uncommon [2]. Clinical trial data show that approximately 4% of adults taking gabapentin for nerve pain reported constipation compared to about 2% taking a placebo. This means gabapentin does increase constipation risk slightly, but the absolute risk remains low.

Medical references list constipation among gabapentin’s gastrointestinal side effects, though it’s less common than dizziness, drowsiness, sleepiness, tiredness, or fatigue. When examining digestive side effects, constipation appears less frequently than nausea or diarrhea [1]. Unlike opioids, which have a well-established mechanism for causing constipation, gabapentin’s impact on bowel function is less direct and less predictable.

The relationship between gabapentin or Neurontin and constipation varies significantly from person to person. Some individuals may notice changes in their bowel habits shortly after starting the medication, while others may take gabapentin for years without experiencing any digestive issues. This variability makes it challenging to predict who will develop constipation and who won’t. Factors such as individual metabolism, existing digestive health, concurrent medications, and lifestyle habits all play a role in determining whether this side effect will occur.

How Common Is It? What the Numbers Say

Research indicates that constipation occurs in approximately 2-4% of people taking gabapentin. To put this in perspective, the general adult population experiences constipation at rates of about 16%. Opioid pain medications cause constipation in 40-95% of users, making gabapentin’s risk significantly lower.

Many factors contribute to constipation, including diet, poor hydration, lack of physical activity, and other medications. When someone experiences constipation while taking multiple medications, it can be difficult to pinpoint which one is responsible. Additionally, some people may not report mild constipation to their healthcare providers, considering it a minor inconvenience rather than a side effect worth mentioning.

Certain groups face higher risks. Older adults are more likely to experience constipation due to age-related changes. People who take gabapentin with opioids face particularly elevated risks since both medications can slow bowel function. Studies have shown that when gabapentin and opioids [3] are combined, the risk of constipation can increase substantially compared to taking either medication alone. This is especially relevant for individuals managing chronic pain conditions who may require multiple medications for adequate symptom control.

Why Does Gabapentin Cause Constipation?

The mechanism isn’t completely understood, but several theories exist. The digestive tract has its own nervous system called the enteric nervous system, which controls gut motility. When gabapentin affects nerve signaling throughout the body, it may inadvertently slow the muscle contractions that move stool through the intestines.

Some researchers believe that gabapentin’s effects on calcium channels may play a role. These channels are present not only in the brain and spinal cord but also in the smooth muscles of the intestinal wall. By modulating these channels, gabapentin might reduce the coordinated contractions needed for normal bowel movements.

Drug interactions also play a role. When gabapentin is combined with constipating medications, particularly opioids, the effects compound, creating greater constipation risk than either medication alone. This is particularly important for people managing chronic pain who may be prescribed both types of medications simultaneously.

Signs and Symptoms to Watch For

Medical definitions identify constipation as having fewer than three bowel movements per week. Signs include hard or lumpy stools, straining during bowel movements, a feeling of incomplete emptying, abdominal bloating, and reduced appetite.

If you’ve recently started gabapentin or increased your dose, pay attention to changes in your bowel habits. Many common side effects of gabapentin appear within the first few weeks of starting or increasing a regular gabapentin dose.

Contact your healthcare provider if you’re unable to pass stool for more than three days, experience severe abdominal pain, notice blood in your stool, develop nausea and vomiting along with constipation, or experience unexplained weight loss.

Management and What Can Be Done

If you develop constipation while taking gabapentin, several strategies can help.

Lifestyle and Diet Adjustments

Increasing dietary fiber is one of the most effective approaches. Aim for 25-30 grams daily through fruits, vegetables, whole grains, beans, and legumes. Drink six to eight glasses of water daily to help soften stool. Regular physical activity, like a 20-30 minute daily walk, can help maintain regular bowel movements. Establish a consistent bathroom routine, particularly after meals.

Making these changes gradually is important. If you suddenly increase your fiber intake without adequate hydration, you may actually worsen constipation or experience uncomfortable bloating and gas. Start by adding one or two high-fiber foods to your daily diet and increasing your water intake simultaneously. Over the course of a week or two, gradually work up to the recommended level. This gentle approach allows your digestive system to adjust, typically producing better long-term results.

Over-the-Counter Treatment Options

People can use over-the-counter treatments if lifestyle changes do not produce any results. The treatment options for constipation include stool softeners with docusate sodium, fiber supplements with psyllium, and osmotic laxatives containing polyethylene glycol. Always consult your healthcare provider for medical advice before starting any laxative.

Re-evaluating Medication Strategy

If constipation becomes severe or persistent, consult your healthcare provider to discuss alternative treatments. Options include reducing your gabapentin dose, switching to a different medication, or adding medications to counteract constipation. The key is early communication.

Risk Factors for Constipation

Age is a significant factor. Older adults are more likely to experience constipation due to a slower metabolism and decreased physical activity. If you’re over 65 and starting gabapentin, being proactive about hydration, fiber, and physical activity is especially important.

Your baseline diet and lifestyle have a considerable impact. A diet low in fiber and high in processed foods increases constipation risk. Inadequate fluid intake and a sedentary lifestyle compound the problem.

Concurrent medication use creates the highest risk, particularly the combination of gabapentin and opioids. Both medications can slow gut motility, creating a synergistic effect that makes constipation more likely.

Getting Support at Epiphany Wellness

At Epiphany Wellness, we understand that managing medications and their side effects can be challenging, especially when you’re working toward recovery. Many of our clients take gabapentin as part of their comprehensive treatment plans, and we recognize that medication management is a crucial component of overall wellness.

Our outpatient programs, including our Partial Hospitalization Program (PHP) and Intensive Outpatient Program (IOP), provide supportive environments where you can address both your primary treatment needs and medication management concerns. We work collaboratively with healthcare providers to ensure you receive comprehensive care that considers all aspects of your well-being, including how medications such as gabapentin may affect your daily life and comfort.

Conclusion

Does gabapentin cause constipation? Yes, it can, but this side effect occurs in only about 2-4% of users. Most people take this medication without experiencing significant bowel changes. Understanding your risk factors, particularly if you’re older or taking other constipating medications, helps you take preventive measures.

If you develop constipation after starting gabapentin, effective management strategies exist. Lifestyle modifications, such as increasing fiber and water intake, staying physically active, and establishing regular bathroom habits, often provide relief.

The important takeaway is that constipation doesn’t necessarily mean you must stop taking gabapentin. Open communication with a healthcare professional allows you to address this side effect while continuing to benefit from the medication.

If you’re experiencing concerns with gabapentin, speak with your healthcare provider. At Epiphany Wellness, we’re here to support you through all aspects of your health journey.