Can a steroid injection cause diarrhea?

October 9, 2025 •

4 min read

According to one study involving epidural steroid injections, gastrointestinal problems were noted as a systemic reaction in a small percentage of patients, confirming that a steroid injection can cause diarrhea, though it is not a primary or common side effect. Understanding this potential risk is important for patients undergoing treatment.

Quick Summary

A steroid injection can cause diarrhea, but it is an uncommon side effect resulting from systemic absorption of the medication. This temporary gastrointestinal upset is much less frequent than with oral steroids. It is typically mild and resolves on its own within a short time.

Key Points

Diarrhea is a possible side effect of steroid injections: Although uncommon, systemic absorption of corticosteroids from an injection can lead to gastrointestinal side effects like diarrhea.
Frequency is lower than with oral steroids: Injections are less likely to cause systemic GI side effects compared to oral corticosteroids because of lower overall systemic exposure.
Systemic effects can influence gut motility and health: Steroids can alter the movement of the digestive tract and affect the balance of gut bacteria, which may cause diarrhea.
Duration of symptoms is typically short: Any GI upset from a steroid injection is usually temporary and often resolves within a few days to a week.
Risk increases with dosage and combination with other drugs: Higher doses and co-administration with other medications like NSAIDs can increase the risk and severity of gastrointestinal issues.
Stay hydrated and manage diet to ease symptoms: If diarrhea occurs, staying hydrated and eating bland foods can help manage the discomfort until the symptom subsides.

Corticosteroid injections are a powerful tool used to reduce localized inflammation and pain associated with conditions such as arthritis, bursitis, and tendonitis. While their primary effect is targeted to a specific area, a portion of the medication is absorbed into the bloodstream, where it can cause systemic side effects. While diarrhea is not the most common adverse effect, it is a documented possibility. This article explores the pharmacological mechanisms behind this reaction, compares the risk to oral steroids, and offers guidance on managing the symptom.

The Mechanism Behind Steroid-Induced Diarrhea

When corticosteroids are injected, the medication is absorbed by the body, entering the systemic circulation. This can affect various bodily functions, including the digestive system. The mechanism by which this leads to diarrhea is not fully understood but may involve several factors working in tandem.

Effects on Gastrointestinal Motility

Steroids are known to influence gastrointestinal (GI) motility, which is the movement of food through the digestive tract. While some individuals experience a slowing of this process, leading to constipation, others may have the opposite effect, resulting in increased bowel movements and diarrhea. This can also be linked to electrolyte imbalances, such as decreased blood potassium levels (hypokalemia), which can affect muscle function in the gut.

Impact on Gut Microbiome

Emerging research suggests that corticosteroids can alter the delicate balance of the gut microbiota—the community of microorganisms living in the intestines. An imbalance, or dysbiosis, can lead to digestive disturbances, including changes in stool consistency. Steroid use has been shown to decrease the diversity of gut bacteria, which can affect gut health and function.

Systemic Influence on Inflammation and the Gut Lining

Although steroid injections are used to reduce inflammation, systemic absorption of the medication can paradoxically affect the gut lining. High doses or frequent use of corticosteroids, particularly when combined with non-steroidal anti-inflammatory drugs (NSAIDs), can increase the risk of gastritis, stomach ulcers, and intestinal bleeding, though this is more commonly associated with oral administration. Any such irritation can lead to digestive discomfort and changes in bowel habits.

Factors Influencing the Risk of Diarrhea

The likelihood of experiencing diarrhea after a steroid injection can vary based on several factors. These include:

Dosage and Frequency: Higher doses and more frequent injections of corticosteroids increase the risk of systemic side effects. A single, low-dose injection is less likely to cause a significant systemic reaction than repeated injections over time.
Individual Sensitivity: Every patient reacts differently to medications. Some individuals may be more sensitive to the systemic effects of corticosteroids and therefore more prone to developing diarrhea or other GI symptoms.
Type of Steroid: Different corticosteroids have varying potencies and half-lives, which can influence the extent of systemic absorption and the risk of side effects.
Combination with Other Medications: Taking steroids alongside other medications, such as NSAIDs, significantly increases the risk of gastrointestinal complications like ulcers and bleeding. This can contribute to or exacerbate diarrhea.

Comparison of Injected vs. Oral Steroids and GI Side Effects

It is important to differentiate between the potential side effects of injected and oral corticosteroids, as the route of administration significantly impacts the risk of systemic reactions, including gastrointestinal issues.


Feature	Injected Corticosteroids	Oral Corticosteroids (e.g., Prednisone)
Route of Absorption	Local, but some systemic absorption occurs.	Systemic absorption via the gastrointestinal tract.
Likelihood of Diarrhea	Possible but uncommon; systemic side effects are less likely.	More common due to higher systemic levels and direct GI exposure.
Common GI Issues	Typically mild and temporary GI upset.	Nausea, vomiting, indigestion, bloating, diarrhea, increased risk of ulcers, and bleeding.
Duration of GI Effects	Usually resolve within a few days to a week.	Can last as long as the medication is taken, especially with long-term use.
Severity of GI Effects	Generally mild and self-limiting.	Can range from mild discomfort to severe complications like bleeding or perforation.

Managing and Preventing Steroid-Related Diarrhea

If you experience diarrhea after a steroid injection, several strategies can help manage the symptoms, though they often resolve quickly on their own.

Stay Hydrated: Diarrhea can lead to dehydration. Drinking plenty of fluids, such as water and electrolyte-containing drinks, is crucial.
Adjust Your Diet: Focus on eating bland, low-fiber foods. Avoiding spicy or fatty foods can help reduce intestinal irritation.
Avoid Irritants: Refrain from consuming alcohol and caffeine, as these can exacerbate GI issues.
Report Persistent Symptoms: If diarrhea is severe, persistent, or accompanied by other concerning symptoms, such as fever or abdominal pain, contact your healthcare provider.
Discuss Medications: Always inform your doctor about all medications you are taking, especially NSAIDs, to minimize the risk of compounding side effects.

Conclusion

In summary, a steroid injection can, on rare occasions, cause diarrhea, but this is a much less common side effect than when steroids are taken orally. The risk depends on factors like dosage, frequency, and individual sensitivity. The symptoms are typically mild, temporary, and result from systemic absorption of the corticosteroid. Anyone experiencing severe or persistent gastrointestinal side effects after a steroid injection should seek medical advice. Proper management and awareness of risk factors are key to minimizing discomfort while benefiting from the therapeutic effects of the medication. For more information on side effects, consulting reliable sources such as the Hospital for Special Surgery's educational content on corticosteroids can be beneficial.

Frequently Asked Questions

Diarrhea from a steroid injection is relatively uncommon. Systemic side effects, including gastrointestinal problems, occur in a small percentage of patients. A study on epidural injections noted GI issues in about 10.2% of systemic reactions, with diarrhea making up a small fraction of those cases.

If diarrhea occurs, it is usually temporary. Most patients experience symptoms for only a few days, and they should resolve on their own within about a week.

Yes, oral corticosteroids are more likely to cause systemic side effects, including diarrhea, than injected steroids. This is because the oral route leads to higher and more consistent levels of the medication throughout the body.

While not fully understood, the mechanism involves the systemic absorption of the steroid, which can affect gastrointestinal motility and alter the balance of the gut microbiota. This can cause changes in bowel habits, including diarrhea.

You should contact your healthcare provider immediately. While mild diarrhea can be managed with home care, severe or persistent symptoms, or those accompanied by fever or abdominal pain, require medical evaluation.

Yes, dietary adjustments can help. Focus on a bland diet and ensure you are well-hydrated. Avoid spicy, fatty, or high-fiber foods that can irritate the gut. Also, reduce consumption of alcohol and caffeine.

Yes, while rare for injections, systemic absorption can cause other GI issues. This includes nausea, upset stomach, and, more seriously, an increased risk of ulcers or bleeding, especially when combined with NSAIDs.