A Comprehensive Guide: What is Xifaxanta Used For?

October 6, 2025 •

3 min read

Clinical studies show that Xifaxanta (rifaximin) provides long-lasting relief for symptoms of irritable bowel syndrome with diarrhea (IBS-D) in some patients. This unique, non-systemic antibiotic is also approved to prevent a recurrence of hepatic encephalopathy and to treat traveler's diarrhea caused by E. coli.

Quick Summary

Xifaxanta (rifaximin) is an antibiotic that treats irritable bowel syndrome with diarrhea, traveler's diarrhea from E. coli, and prevents hepatic encephalopathy recurrence by acting locally on gut bacteria.

Key Points

Primary Uses: Xifaxanta (rifaximin) is FDA-approved to treat traveler's diarrhea caused by E. coli, irritable bowel syndrome with diarrhea (IBS-D), and to prevent the recurrence of hepatic encephalopathy (HE).
Local Action: As a non-systemic antibiotic, Xifaxanta works primarily within the gut, with minimal absorption into the bloodstream, which helps limit systemic side effects.
Targeted Treatment: It reduces symptoms by inhibiting the growth of specific bacteria in the intestines, which can alleviate conditions related to bacterial imbalance.
Off-Label Application: Doctors often prescribe Xifaxanta off-label to treat Small Intestinal Bacterial Overgrowth (SIBO), a condition where excess bacteria populate the small intestine.
Usage Varies by Condition: Treatment length and dosage differ significantly depending on the condition being treated, from a short 3-day course for traveler's diarrhea to longer maintenance therapy for HE.
Potential Side Effects: While generally well-tolerated, common side effects can include nausea, fatigue, and dizziness. Severe side effects like C. difficile infection are rare but possible.
Not for All Diarrhea: It is ineffective for traveler's diarrhea that includes fever or blood in the stool, or for viral infections like the common cold or flu.

What is Xifaxanta (Rifaximin)?

Xifaxanta, generically known as rifaximin, is a unique, oral, non-systemic antibiotic that works primarily in the gastrointestinal tract. Unlike many other antibiotics that are absorbed into the bloodstream and affect the whole body, Xifaxanta is poorly absorbed and remains in the gut. This targeted action allows it to combat specific bacteria in the intestines without widespread systemic effects. It accomplishes this by binding to bacterial RNA polymerase, thereby inhibiting bacterial RNA synthesis and controlling bacterial populations. This mechanism makes it a valuable tool for managing several distinct gastrointestinal and liver-related conditions.

FDA-Approved Uses for Xifaxanta

Xifaxanta is approved by the U.S. Food and Drug Administration (FDA) for three primary conditions in adults:

Irritable Bowel Syndrome with Diarrhea (IBS-D): For patients whose primary symptoms are abdominal pain and diarrhea, Xifaxanta is a short-term, 14-day treatment. It is particularly effective for those who do not have constipation as a primary symptom.
Hepatic Encephalopathy (HE): In adults with severe liver disease, toxins normally cleared by the liver, like ammonia, can build up in the bloodstream and reach the brain, causing confusion and altered mental status. Xifaxanta is used to reduce the risk of recurring HE episodes by decreasing the amount of toxin-producing bacteria in the gut.
Traveler's Diarrhea: Xifaxanta is prescribed for diarrhea caused by non-invasive strains of Escherichia coli (E. coli). The treatment course is typically short, lasting only three days. It is important to note that it is not indicated for traveler's diarrhea accompanied by fever or blood in the stool.

Targeting the Gut Microbiome

The efficacy of Xifaxanta in these conditions is largely due to its specific action on the gut microbiome. By modulating the bacterial population in the digestive tract, it helps restore a more balanced microbial environment. This is crucial for managing symptoms associated with an overgrowth or imbalance of certain gut bacteria.

Off-Label Use: Small Intestinal Bacterial Overgrowth (SIBO)

While not FDA-approved for this purpose, Xifaxanta is commonly prescribed off-label for Small Intestinal Bacterial Overgrowth (SIBO). SIBO is a condition where there is an excessive amount of bacteria in the small intestine, leading to symptoms like bloating, gas, abdominal pain, and diarrhea. Doctors may prescribe Xifaxanta to help eradicate the bacterial overgrowth and alleviate these symptoms. The dosage and duration can vary, with clinical studies exploring different regimens, though a 10 to 14-day course is common.

How Xifaxanta Differs from Other Medications

For conditions like IBS-D, Xifaxanta stands apart from traditional antidiarrheal or antispasmodic medications due to its targeted action on gut bacteria. It addresses a potential root cause rather than just masking symptoms.


Feature	Xifaxanta (Rifaximin)	Viberzi (Eluxadoline)	Bentyl (Dicyclomine)
Mechanism	Non-systemic antibiotic; modifies gut bacteria.	Antidiarrheal; acts on opioid receptors in intestines.	Anticholinergic; relaxes smooth muscles in the gut.
Target	Gut bacteria believed to contribute to symptoms.	Opioid receptors in the gut to reduce pain and motility.	Muscle spasms in the gut.
FDA-Approved Uses	IBS-D, HE, Traveler's Diarrhea.	IBS-D.	IBS (muscle spasms).
Treatment Type	Primarily short-term (IBS-D) or maintenance (HE).	Continuous, twice-daily dosing.	Continuous, multiple-times-daily dosing.
Unique Considerations	Works primarily in the gut with minimal systemic absorption.	Controlled substance; potential for pancreatitis, especially in those without a gallbladder or heavy drinkers.	Anticholinergic side effects (dry mouth, blurred vision).

Important Considerations and Side Effects

While generally well-tolerated, Xifaxanta can cause side effects and is not suitable for everyone. Patients should discuss their medical history with their doctor, especially concerning liver health. Common side effects observed in clinical trials include:

For IBS-D: Nausea and increased liver enzymes.
For HE: Swelling in the ankles or feet, fatigue, nausea, constipation, dizziness, and insomnia.
Other general side effects: Some individuals experience headache, fatigue, or muscle spasms.

Serious side effects are rare but possible. These include severe skin rashes and Clostridioides difficile (C. diff) infection, as with other antibiotics. Xifaxanta should not be used in individuals with a known hypersensitivity to rifamycins.

Conclusion

Xifaxanta is a targeted antibiotic with multiple FDA-approved uses for gastrointestinal conditions, including IBS-D, hepatic encephalopathy, and traveler's diarrhea caused by specific bacteria. Its unique, non-systemic mechanism allows it to act locally in the gut to reduce bacterial overgrowth and modulate the gut environment. For patients with IBS-D, it offers a distinct treatment approach compared to other symptom-focused medications. While effective, it is a prescription medication that should be used under medical supervision, with its specific indications and potential side effects carefully considered.

For more detailed information on specific uses and prescribing details, consult the MedlinePlus drug information page for Rifaximin.

Frequently Asked Questions

The duration of Xifaxanta treatment depends on the condition. For traveler's diarrhea, it's typically taken for 3 days. For irritable bowel syndrome with diarrhea (IBS-D), a treatment course lasts 14 days and can be repeated up to two times. For hepatic encephalopathy, it may be a long-term, continuous medication.

No, Xifaxanta is an antibiotic and is not effective against viral infections, such as the common cold or the flu. Using it for a viral illness is not only ineffective but can contribute to antibiotic resistance.

Xifaxanta is commonly used off-label to treat Small Intestinal Bacterial Overgrowth (SIBO). Although it is not FDA-approved for this specific condition, studies have shown it to be effective in managing SIBO-related symptoms, often prescribed for a 10 to 14-day course.

Common side effects can include nausea, peripheral edema (swelling), constipation, fatigue, dizziness, and headache. Specific side effects can vary depending on the condition being treated.

Individuals who are allergic to rifaximin or other rifamycin antibiotics should not take Xifaxanta. Caution is also advised for those with severe liver impairment, as this can increase the effects of the medication. It is also not suitable for certain types of traveler's diarrhea with fever or bloody stool.

Xifaxanta is a treatment for the symptoms of irritable bowel syndrome with diarrhea (IBS-D), but it is not considered a cure. It can provide symptom relief for several weeks, and repeat courses of treatment are possible if symptoms return.

Unlike medications that target muscle spasms (like Bentyl) or opioid receptors (like Viberzi), Xifaxanta is an antibiotic that works by altering the gut bacteria composition, addressing a potential root cause of the diarrhea and pain associated with IBS-D.

Yes, Xifaxanta is considered safe and well-tolerated for the long-term management of recurrent hepatic encephalopathy. In contrast, treatment for IBS-D is typically limited to repeated short courses, and studies are ongoing regarding its long-term use for other conditions.