Can Antibiotics Bring Relief to People With IBS?

Medically Reviewed by Minesh Khatri, MD on July 29, 2021

If you have irritable bowel syndrome (IBS), you know it can be tough to treat. You might already be trying things like changing your diet and working on stress management. Might antibiotics help, too?

Doctors don’t usually prescribe these medicines for IBS because they’re not a standard treatment for this condition. Your doctor probably will recommend things like diet changes and stress management first. And antibiotics are only an option for people with one type of IBS.

The main symptoms of IBS are belly pain with diarrhea or constipation, or sometimes both. Rifaximin (Xifaxan), which doctors often prescribe for traveler’s diarrhea, is the only antibiotic approved for IBS without constipation. Researchers are studying other antibiotics for treating IBS.

Why Antibiotics May Help

Doctors don’t know exactly what causes IBS. One theory is you can get IBS symptoms from an unhealthy balance of gut bacteria. Research suggests that too much bacteria in the small intestine may be common in people with IBS. Antibiotics, which kill bacteria, may help bring the bacteria balance closer to normal.

These medicines may:

  • Make harmful gut bacteria less dangerous
  • Help protect the intestinal lining from bacterial infection
  • Lower inflammation, the body’s attack against bacteria and viruses
  • Preserve healthy bacteria in the colon

Rifaximin for IBS

In studies, rifaximin helped with several symptoms, including bloating, gas, diarrhea, and belly pain.

Some people feel better after taking rifaximin for 10-14 days. If that doesn’t work for you, ask your doctor if you should keep taking it.

Other antibiotics haven’t been as promising for treatment for IBS symptoms. 

Antibiotic Risks

Your gut is filled with good bacteria that help keep you healthy. Antibiotics can upset the balance of bacteria, which might make IBS more likely in some people. They can also let a dangerous bacteria called C. difficile multiply in your gut, which can cause severe -- and sometimes life-threatening -- diarrhea.

What Your Doctor May Suggest First

Your doctor probably will have you try to make several changes first. Depending on your symptoms, these can include:

Diet. Change foods that might cause you trouble.

Counseling or hypnosis. These can help control IBS-related stress and anxiety.

Low-dose antidepressants. They may lower IBS pain.

Anti-diarrhea drugs, such as loperamide (Imodium) or diphenoxylate and atropine (Lomotil)

Laxatives, such as lubiprostone (Amitiza)

Anti-spasm drugs, such as dicycloverine (Bentyl) or hyoscyamine (Anaspaz, Levsin, Symax)

Probiotics. These are live bacteria and yeast that are good for your health. Yogurt and other fermented foods have them.

What to Tell Your Doctor

If your doctor suggests trying rifaximin, let them know:

  • If you have severe liver problems
  • What other drugs or supplements you take, as some may interact with rifaximin
  • If you’re pregnant or planning to be, or if you’re nursing

Whenever you take antibiotics, follow your doctor’s orders to the letter, and tell them if your symptoms get worse or you have new ones.

Show Sources


UpToDate: “Irritable bowel syndrome (Beyond the Basics).”

Gut and Liver: “Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge Between Functional Organic Dichotomy.”

Alimentary Pharmacology & Therapeutics: “Evidence for the Role of Gut Microbiota in Irritable Bowel Syndrome and Its Potential Influence on Therapeutic Targets.”

International Foundation for Functional Gastrointestinal Disorders: “Newer IBS Medications.” “Is Xifaxan Right for Me?”

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