What antibiotics are used to treat ulcerative colitis (UC) or infectious colitis?

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Last updated: April 11, 2025View editorial policy

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From the Guidelines

Antibiotics are not the primary treatment for colitis, and their use should be tailored to the specific type of colitis present. For infectious colitis caused by bacteria like Clostridium difficile, antibiotics such as oral vancomycin (125mg four times daily for 10-14 days) or fidaxomicin (200mg twice daily for 10 days) are recommended 1. However, for inflammatory bowel disease-related colitis like ulcerative colitis or Crohn's disease, antibiotics are not standard treatment and may sometimes worsen symptoms, instead, biologics such as infliximab, adalimumab, golimumab, vedolizumab, tofacitinib or ustekinumab are recommended for induction and maintenance of remission 1.

Some key points to consider when treating colitis with antibiotics include:

  • The use of antibiotics depends on the specific type of colitis present
  • Unnecessary antibiotic use can disrupt gut flora and potentially trigger or worsen colitis, especially C. difficile colitis
  • Proper diagnosis through stool tests, colonoscopy, or imaging is essential before starting any antibiotic treatment for colitis
  • For pouchitis, a condition that can occur after surgical removal of the colon, antibiotics such as ciprofloxacin and/or metronidazole may be used for treatment, and advanced immunosuppressive therapies may be considered for recurrent pouchitis 1
  • The British Society of Gastroenterology suggests that Clostridium difficile infection in acute severe ulcerative colitis should be treated with oral vancomycin, and that patients with moderate to severe colitis should have colonic biopsies to look for cytomegalovirus disease 1.

It's essential to consult with a healthcare provider for appropriate diagnosis and treatment tailored to the specific condition, as the use of antibiotics can have significant consequences on the patient's morbidity, mortality, and quality of life.

From the FDA Drug Label

Vancomycin Hydrochloride Capsules are indicated for the treatment of C. difficile-associated diarrhea. Vancomycin Hydrochloride Capsules are also used for the treatment of enterocolitis caused by Staphylococcus aureus (including methicillin-resistant strains) in adult and pediatric patients less than 18 years of age Vancomycin Hydrochloride Capsules for the treatment of colitis are for oral use only and are not systemically absorbed.

Vancomycin is used to treat colitis caused by C. difficile or Staphylococcus aureus. The recommended dose for C. difficile-associated diarrhea is 125 mg administered orally 4 times daily for 10 days, and for staphylococcal enterocolitis, the total daily dosage is 500 mg to 2 g administered orally in 3 or 4 divided doses for 7 to 10 days 2.

From the Research

Antibiotics for Colitis

  • The use of antibiotics for colitis depends on the cause of the infection, with different antibiotics recommended for different pathogens 3, 4, 5.
  • For infectious colitis caused by invasive bacterial enteropathogens such as Shigella, Salmonella, and Campylobacter, empiric treatment with azithromycin may be recommended 3.
  • For Clostridioides difficile infection, fidaxomicin is recommended as the first line of treatment, with vancomycin as a second choice 4.
  • Metronidazole may still be recommended in certain cases, such as in areas where the strain of Clostridium difficile is susceptible to the antibiotic 4.
  • The management of acute colitis depends on the establishment of the cause, and most forms of infectious colitis are treatable with antimicrobials 5.
  • High dose vancomycin may be used in the treatment of severe C. difficile infection, but the evidence is weak and more research is needed to define its role 6.

Specific Antibiotics

  • Azithromycin: recommended for empiric treatment of febrile dysenteric diarrhea caused by invasive bacterial enteropathogens 3.
  • Fidaxomicin: recommended as the first line of treatment for Clostridioides difficile infection 4.
  • Vancomycin: recommended as a second choice for Clostridioides difficile infection, and may be used in high doses for severe cases 4, 6.
  • Metronidazole: may still be recommended in certain cases of Clostridioides difficile infection, but its use is not universally endorsed 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Approach to the patient with infectious colitis.

Current opinion in gastroenterology, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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