Can cefuroxime cause diarrhea? What you need to know about this common side effect

October 11, 2025 •

4 min read

According to clinical trial data, diarrhea is one of the most common side effects of the antibiotic cefuroxime. This gastrointestinal issue, which can range from mild to severe, is a frequently reported complication for those taking this medication.

Quick Summary

Cefuroxime frequently causes diarrhea by disrupting the gut's normal bacteria. While often mild and temporary, it can signal a more serious condition like a C. difficile infection. Management includes hydration, dietary changes, and sometimes probiotics, but severe or bloody diarrhea requires immediate medical attention.

Key Points

Cefuroxime is a Common Cause of Diarrhea: Like many antibiotics, cefuroxime frequently causes diarrhea, a common side effect reported in clinical trials.
Diarrhea Mechanism: The medication disrupts the gut's normal bacteria, which can lead to an overgrowth of harmful microbes or an imbalance that causes loose stools.
C. difficile Risk: A potentially serious complication is a C. difficile infection, which can cause severe, watery, or bloody diarrhea and may occur weeks after stopping the medication.
Managing Mild Diarrhea: Strategies include taking cefuroxime with food, staying hydrated, consuming probiotics (separated from the antibiotic dose), and eating bland foods.
When to Seek Medical Help: Severe, watery, bloody, or persistent diarrhea, along with fever or intense abdominal pain, requires immediate medical attention.
Avoid Self-Medicating: Do not take over-the-counter anti-diarrheal medicine without a doctor's approval, as it could worsen a C. difficile infection.

What is Cefuroxime and How Does it Work?

Cefuroxime, known by the brand name Ceftin, is a cephalosporin antibiotic used to treat a variety of bacterial infections, including those of the respiratory tract, skin, and urinary tract. It works by inhibiting the growth of bacteria, specifically by interfering with their cell wall synthesis. Cefuroxime is an effective tool against infection, but like all antibiotics, it comes with a risk of side effects, with gastrointestinal issues being among the most frequent.

The Mechanism Behind Cefuroxime-Induced Diarrhea

The primary reason cefuroxime and other antibiotics can cause diarrhea is the disruption of the natural bacterial balance within the gut, known as the gut microbiome. This disruption occurs through a couple of key mechanisms:

Destruction of beneficial bacteria: Cefuroxime is a broad-spectrum antibiotic, meaning it kills a wide range of bacteria, both good and bad. This collateral damage to the beneficial gut flora allows opportunistic pathogens to proliferate.
Overgrowth of opportunistic pathogens: When the normal, healthy gut bacteria are suppressed, harmful bacteria that are resistant to the antibiotic can multiply unchecked.

This imbalance can result in two types of diarrhea:

Mild Diarrhea: In many cases, the disruption to the gut microbiome leads to a mild, temporary osmotic diarrhea. The colon is unable to absorb carbohydrates effectively due to the loss of bacteria that process them. This increased carbohydrate load draws water into the intestines, resulting in loose stools.
Severe Diarrhea (C. diff infection): A more serious complication is an overgrowth of the bacterium Clostridioides difficile (C. diff). This can happen while on the antibiotic or even months after stopping treatment. C. diff releases toxins that damage the lining of the colon, leading to severe, watery, or bloody diarrhea, fever, and abdominal pain. This condition, known as pseudomembranous colitis, requires immediate medical attention.

Managing Mild Diarrhea Caused by Cefuroxime

If you experience mild diarrhea while taking cefuroxime, several strategies can help manage the symptoms:

Take with food: If cefuroxime causes an upset stomach, taking it with food can help reduce gastrointestinal irritation and potentially lessen diarrhea.
Stay hydrated: Diarrhea can lead to dehydration. Drinking plenty of fluids, such as water, broth, and electrolyte-rich beverages, is crucial.
Consume probiotics: Probiotics, which are live beneficial bacteria, can help replenish the gut flora depleted by antibiotics. Taking a probiotic supplement or eating probiotic-rich foods like yogurt can be effective. However, separate probiotic and antibiotic doses by at least two hours.
Adjust diet: Eating bland, low-fiber foods, such as bananas, rice, and applesauce, can help firm up stools. Temporarily avoid spicy or greasy foods, dairy, and high-fiber items.
Consult your doctor: Before taking any anti-diarrheal medication, it is essential to consult a healthcare professional, as these can sometimes worsen a C. diff infection.

When to Contact a Healthcare Provider

While mild diarrhea is common, certain symptoms warrant immediate medical attention. Contact your doctor immediately if you experience any of the following during or after your cefuroxime treatment:

Severe, watery, or bloody diarrhea
Persistent diarrhea that does not improve after the antibiotic course is finished
Fever
Severe abdominal cramps or pain
Nausea and vomiting
Symptoms of dehydration

Comparison of Antibiotic-Associated Diarrhea

To put cefuroxime's effect into perspective, here is a comparison with another common antibiotic, amoxicillin, which is also known to cause antibiotic-associated diarrhea.


Feature	Cefuroxime (Cephalosporin)	Amoxicillin (Penicillin)
Mechanism of Diarrhea	Disruption of gut microbiome, risk of C. diff overgrowth	Disruption of gut microbiome, risk of C. diff overgrowth
Incidence of Mild Diarrhea	Common side effect; reported in clinical trials, often mild	Common side effect; reported in clinical trials
Risk of C. diff Infection	Documented risk, especially with second-generation cephalosporins	Also associated with C. diff, though typically considered a lower risk than some other antibiotic classes
Management	Taking with food, hydration, probiotics, diet adjustment	Taking with food, hydration, probiotics, diet adjustment
Severity	Ranges from mild to severe (C. diff)	Ranges from mild to severe (C. diff)

Conclusion

In conclusion, it is well-established that cefuroxime can cause diarrhea as a side effect. This is primarily due to the antibiotic's effect on the gut microbiome, which can lead to a mild, temporary imbalance or, in more serious cases, a potentially life-threatening C. difficile infection. Most instances of mild diarrhea can be managed with simple dietary adjustments, hydration, and probiotics. However, it is crucial to recognize the signs of a more severe reaction, such as persistent, bloody, or watery diarrhea accompanied by fever and abdominal pain, and seek prompt medical care. The key to safe and effective treatment is to follow your doctor's instructions, finish the full course of medication, and communicate any concerning side effects. Always consult a healthcare professional before self-treating diarrhea with over-the-counter medications while on antibiotics. For more detailed medical information, consult a resource like the NIH's PubMed database.

Frequently Asked Questions

Diarrhea is one of the most common side effects of cefuroxime, with clinical trial data reporting it as a frequent occurrence, often mild in nature.

Cefuroxime disrupts the balance of the gut's normal bacteria. By killing both good and bad bacteria, it allows opportunistic microbes to flourish, leading to an imbalance that causes diarrhea.

You should not take any anti-diarrheal medication without consulting your doctor first. In some cases, these medications can prolong or worsen a serious C. difficile infection.

Prevention can include taking the medication with food, using a probiotic supplement (at least 2 hours before or after the antibiotic dose), and staying hydrated.

Mild diarrhea is often transient and resolves on its own. C. difficile diarrhea is more severe and persistent, often accompanied by fever, severe abdominal cramps, and watery or bloody stools.

Focus on a bland diet with low-fiber foods like bananas, rice, applesauce, and toast. Avoid greasy, spicy, or dairy-heavy foods, and ensure you drink plenty of fluids to stay hydrated.

You should call your doctor if the diarrhea is severe, watery, or bloody, if it is accompanied by fever or severe stomach pain, or if it persists even after you finish the medication.