What is XIFAXAN (zī-fax-an)?

XIFAXAN is a 2 week prescription treatment that provided up to 6 months of relief from IBS-D symptoms of abdominal pain and diarrhea in a clinical trial.*†


Short-course therapy, without needing to take a continuous daily pill


FDA-approved for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults

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#1 doctor prescribed medication approved for IBS-D

*IBS-D = irritable bowel syndrome with diarrhea. In a clinical trial: range of 6 to 24 weeks; average of 10 weeks. You can be retreated up to two times if symptoms come back. Based on aggregated total of all prescribers as of October 2019.

Proven relief from both abdominal pain and diarrhea

Just two weeks of XIFAXAN provided significant relief in adults with IBS-D


of patients saw relief
from abdominal pain compared to
43% placebo


of patients saw relief from
diarrhea compared to
66% placebo


of patients saw relief from
abdominal pain and
diarrhea compared to
37% placebo

Target 1 & 2 Study Design: Two identical, randomized, phase 3 trials conducted over a 3-month period. A total of 1258 patients meeting Rome II criteria for IBS received XIFAXAN 550 mg 3 times a day (n=624) or placebo (n=634) for 14 days. Primary endpoint was adequate relief of IBS signs and symptoms for at least 2 of 4 weeks during the month following 14 days of treatment. Adequate relief was defined as a response of “yes” to the weekly Subject Global Assessment (SGA) question: “In regards to your IBS symptoms, compared to the way you felt before you started study medication, have you, in the past 7 days, had adequate relief of your IBS symptoms? [Yes/No].” Primary endpoint: 41% of patients (254 of 624) in the XIFAXAN 550 mg group, 31% of TARGET 1 placebo group (98 of 314) and 32% of TARGET 2 placebo group (103 of 320) experienced adequate relief of IBS signs and symptoms. Composite endpoint was defined as ≥30% decrease from baseline in abdominal pain with a weekly average stool consistency score of <4 (loose stool) for ≥2 weeks during the month following 2 weeks of treatment.

Short-term treatment, long term relief

After just two weeks of treatment, relief lasted for up to 6 months*

*In a clinical trial: range of 6 to 24 weeks; average of 10 weeks of relief from abdominal pain and diarrhea. You can be retreated up to 2 times if symptoms return.

Target 3 Study Design: XIFAXAN was evaluated in 2438 IBS-D patients. 44% (n=1074) experienced relief from a course of treatment. Relief was defined as experiencing a ≥30% improvement from baseline in the weekly average abdominal pain score (based on daily self-reports) and a ≥50% reduction in the number of days in a week with a daily stool consistency of Bristol Stool Scale type 6 or 7 (mushy or watery) for ≥ 2 weeks during the month following 2 weeks of treatment. If patients experienced a recurrence of either of their symptoms for 3 weeks of a rolling 4-week period, they were then randomized to receive a repeat treatment with either XIFAXAN or placebo. The primary endpoint was the proportion of patients who experienced relief in both symptoms (defined exactly as in the first treatment period) during the 4 weeks following repeat treatment.


XIFAXAN is a short-term treatment that you take 3 times a day for 2 weeks.

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Follow your doctor’s instructions exactly when taking XIFAXAN

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XIFAXAN comes in a tablet form for oral administration

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XIFAXAN tablets can be taken with or without food

Artistic rendering of a tablet

You can be retreated up to 2 times if symptoms come back

Most common side effects

In clinical studies, the most common side effects with XIFAXAN for IBS-D were:

  • Nausea (feeling sick to your stomach)
  • An increase in liver enzymes

Constipation was observed in only 0.5% of XIFAXAN patients.

Nausea was observed in 3% of patients taking XIFAXAN vs 2% taking placebo.
Liver enzymes increase observed in 2% of patients taking XIFAXAN vs 1% taking placebo.

Most common side effects
Safety profile

XIFAXAN has a well-established Safety Profile

  • NOT a controlled substance
  • NOT contraindicated in patients without a gallbladder
  • No association of pancreatitis was observed in patients taking XIFAXAN in the clinical trials

XIFAXAN is an antibacterial medication, or antibiotic, that did not cause any clinically relevant antibiotic resistance after 1 to 3 treatment cycles. If you take antibiotics, like XIFAXAN, there is a chance you could experience diarrhea caused by an overgrowth of bacteria (C. difficile). This can cause symptoms ranging in severity from mild diarrhea to life-threatening colitis. Contact your healthcare provider if your diarrhea does not improve or worsens.

How it works

The exact cause of IBS-D is unknown. However, it is believed that an imbalance in gut bacteria may be linked to IBS-D symptoms. XIFAXAN works mainly in the gut to inhibit the growth of bacteria. Talk to your healthcare provider before taking XIFAXAN if you have severe hepatic (liver) impairment, as this may cause increased effects of the medicine.

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