Crohn’s disease is an inflammatory bowel disease that occurs in the gastrointestinal tract. For people with Crohn’s, antibiotics may help lower the level of bacteria in the intestines, which may relieve symptoms.

Antibiotics work to control infections. They may also aid in healing abscesses and fistulas, which connect loops of intestine to each other and connect your intestine to your bladder.

Fistulas and abscesses occur in about one-fourth of people with Crohn's disease. Abscesses often need to be drained, or surgery may sometimes be suggested.

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There are a few possible antibiotic medications for Crohn’s disease that include:


A 2013 study on antimicrobials showed that metronidazole, often sold under the brand name Flagyl, can help battle anaerobic bacteria. This type of bacteria is able to live without oxygen.

Eliminating these bacteria may help reduce your risk of infection and inflammation. This may relieve some of the symptoms of Crohn’s.

Side effects of metronidazole may include numbness and tingling in your extremities, and muscle pain or weakness.

It is important to be aware that drinking alcohol while taking metronidazole may also cause side effects. Nausea and vomiting, and in rare instances, an irregular heartbeat may occur. Make sure to contact your doctor if you experience any of these symptoms.


Cipro (ciprofloxacin) is also prescribed to fight infection in Crohn’s patients. Consistent levels of medication in the bloodstream need to be maintained at all times, so it’s important not to miss doses.

Tendon rupture can be a side effect, although this is rare. Other possible side effects include nausea, vomiting, diarrhea, and abdominal pain.


Xifaxin (rifaximin) has been used for years to treat diarrhea. However, one study showed that it is also effective in treating Crohn’s.

Possible side effects may include:

  • skin rash or hives
  • bloody urine or diarrhea
  • fever

Rifaximin may also be costly, so it’s important to ensure your insurance covers it before picking up your prescription.


Ampicillin is another medication that may help reduce Crohn’s symptoms. This drug is in the same family as penicillin and usually takes effect within 24 to 48 hours.

Side effects may include:

  • diarrhea
  • nausea
  • rashes
  • inflammation and redness of the tongue


Gantanol (sulfonamide) works to help prevent bacteria growth. This medication contains sulfa and allergies to this ingredient are common.

It’s best to be in close contact with your doctor’s office when beginning treatment.

Symptoms of a possible sulfa allergy include rash, itching, or difficulty breathing.

Also, more severe side effects may include:

  • Stevens-Johnson syndrome, a potentially fatal skin rash
  • blood disorders
  • liver damage


Tetracycline is prescribed for a variety of infections. It also inhibits bacteria growth.

Possible side effects of tetracycline include:

  • mouth sores
  • nausea
  • changes in skin color

Antibiotics may help control your symptoms, but they may not affect the progression of Crohn's disease. In some cases people stop taking antibiotics when they feel the side effects of the medication may be more severe than Crohn’s symptoms.

Remember, everyone responds to treatment differently. Be sure to discuss your options with your doctor to find out if antibiotics may be effective for you.