1. Health
Send to a Friend via Email

Discuss in my forum

Barbara Bradley Bolen, Ph.D.

The Two-Week Xifaxan for IBS Study

By January 9, 2011

Follow me on:

Big headlines regarding IBS last week as major news outlets picked up the story of a new study on Xifaxan as a treatment for IBS. Although the study results were positive, (hooray!), to me the headlines were misleading in that they implied that IBS can now be cured with a two week trial of this particular antibiotic. Let's look at the background behind the study and the details of the study itself:

Xifaxan (rifaximin) is an antibiotic that has been used by researchers who have looked at small intestine bacteria overgrowth (SIBO) as a possible contributing cause for IBS. Xifaxan is not absorbed in the stomach and thus is thought to be available to act upon bacteria in the large and small intestine. Because of promising results in terms of testing the SIBO theory, the medication is now undergoing clinical trials for FDA approval as a treatment for IBS without constipation. This new study was undertaken and sponsored by the pharmaceutical manufacturer as part of the FDA approval process.

As for the current study, the number of participants was sizable, with 1260 patients enrolled and a total of 90 percent completing the entire study. All patients suffered IBS without constipation. Patients were randomly assigned to receive 550 mg of Xifaxan three times a day or a placebo for a total of two weeks. Data was collected regarding IBS symptoms for an additional ten weeks.

The results showed that Xifaxan was significantly more likely than placebo to result in patient report of "adequate relief" of IBS symptoms, bloating, and abdominal pain. This symptom alleviation was seen to have held through the ten weeks following the administration of the meds. Side effects were minimal and similar for both the treatment group and the placebo group.

Now for the problem with the headlines. A close look at the numbers shows that the numbers of individuals who experienced symptom relief with the medication were not all that much higher than those who recieved a placebo. Forgive my rounding of the numbers, but the percentage of individuals who benefited from Xifaxan was about 40 to 50 percent for all assessed symptoms, while about 30 percent of placebo patients experienced symptom relief for all assessed symptoms. As you can see, Xifaxan does offer a viable treatment for some patients - just not all patients!

Please know that I am glad to hear that Xifaxan can help some patients - we all know that such help is sorely needed. I just worry about hopelessness kicking in for those who do not experience the miraculous results implied by the news media. IBS appears to have many causes, therefore for many people, a variety of treatment strategies will be needed.

In case you are interested, I have been blogging about the approval process for Xifaxan:

Related Reading:


Pimental, M., et.al. "Rifaximin Therapy for Patients with Irritable Bowel Syndrome without Constipation" New England Journal of Medicine 2011 364:22-32.

| Facebook | Twitter | Newsletter Signup | Forum |

January 20, 2011 at 3:15 pm
(1) jeffiam says:

In his book “A New IBS Solution,” Dr. Mark Pimentel, perhaps the father of the SIBO theory of IBS, points out that not all his patients with bacterial overgrowth realize symptom relief after taking rifaximin. But many do, which is good.

In my case, having been diagnosed with small intestine bacterial overgrowth, I took rifaximin for 2 weeks (500 mg 2x/day) and achieved only modest symptom relief, which didn’t last long. By contrast, I’m now taking amoxicillin and metronidazole, and in just a few days, my dominant symptom–excessive gas–is gone.

For reference, I tend toward IBS-C. It sounds like rifaximin may be more beneficial to IBS-D sufferers.

January 20, 2011 at 8:18 pm
(2) Dr. Bolen says:

Jeffiam, thanks for taking the time to share your own personal experience. Antibiotics offer an intriguing new approach to IBS treatment – I am glad that clinical trials as to safety are underway.

February 6, 2011 at 5:35 pm
(3) Mara Zuniga says:

Despite what the study reports, Xifaxan cannot be so specific that some fo the beneficial bacteria in the large bowel remain untouched. Many people will have the bad bacteria depleted from a regime of Xifaxan and down the road a few months the IBS will return because the dysbiosis will return and now they will have few beneficial bacteria as when they first initiated Xifaxan. They way I got better was to take a probiotic (VSL#3) to repopulate.

February 7, 2011 at 12:23 pm
(4) Dr. Bolen says:

Mara, thanks for taking the time to share your “from the trenches” experience.

July 28, 2011 at 12:43 pm
(5) Pattie says:

This is my third round with Xifaxan. It has worked for me. I have suffered with the bloating and painful stomach. It will be effective for around 5-6 months. Which is wonderful. Thank god my dr has given me samples each time because my insurance doesnt pay for. It is crazy that we pay out to these insurances and they dont cover the meds we need ( THAT WORK).

January 5, 2013 at 1:18 am
(6) nellie says:

i can see why insurance companies are hesitant to cover it, at nearly $2,000 for one two-week round! My eyes nearly welled with tears when my insurance company actually covered it. I’ve just started treatment, along with a major diet adjustment (no wheat, dairy or certain potential histomine contributors) added fiber supplements and 580million in high-end probiotic daily. i also am taking aloe vera (drinking) to help calm inflamation & hopefully heal faster. after 5 days, no noticeable/sufferable side effects. still some pain from eating and some slight abnormalities in my digestion, but I’m being very diligent and I’m determined to do everything i can to make treatment a success. good luck to all that suffer through the illness, tests and treatment attempts. i never wanted to spend this much energy and focus on someing i always took for granted…those were the days! what i wouldnt give to never have to think about ibs again…

February 28, 2013 at 11:38 pm
(7) Linda says:

As a patient on Xifaxin for several years now as I have Crohn’s Disease. Although it is costly, it works amazingly for me. My daughter, who works in the healthcare field, contracted C-diff from a patient. She was treated with Flagyl but even after she had two rounds of Flagyl the diarrhea continued. They did a colonoscopy to check for Crohn’s Disease in her and it was negative. Still the running to the bathroom continued. I called my GI Specialist several times after this colonoscopy and asked nicely if they would let her try Xifaxin. I couldn’t even get them to call me or her back. I finally gave her three pills of mine. It was like a miracle. After only three pills…it stopped. She had suffered for months. We meet with this GI specialist next week and I’m going to push for her to write a script for her for this just in case this comes back in the future. Good product! Expensive, but good!!

Leave a Comment

Line and paragraph breaks are automatic. Some HTML allowed: <a href="" title="">, <b>, <i>, <strike>
Top Related Searches
  • xifaxan
  • domingo enero
  • ©2014 About.com. All rights reserved.

    We comply with the HONcode standard
    for trustworthy health
    information: verify here.