Antibiotic Treatment for Colitis

Types of Colitis and First-Line Antibiotic Choices

The European Society of Clinical Microbiology and Infectious Diseases recommends metronidazole 500 mg three times daily orally for 10 days for non-severe C. difficile colitis 1, 2
The European Society of Clinical Microbiology and Infectious Diseases recommends vancomycin 125 mg four times daily orally for 10 days for severe C. difficile colitis 1, 3
For recurrent C. difficile colitis, the European Society of Clinical Microbiology and Infectious Diseases recommends vancomycin 125 mg four times daily orally for at least 10 days 1, 3
For ulcerative colitis, no antibiotic regimen is generally recommended, including acute severe disease, according to the European Society for Clinical Nutrition and Metabolism 4

The European Society of Clinical Microbiology and Infectious Diseases recommends assessing disease severity to guide treatment choice, with factors indicating severe disease including fever, rigors, and hemodynamic instability 3
The European Society of Clinical Microbiology and Infectious Diseases advises avoiding antiperistaltic agents and opiates in C. difficile infection, and discontinuing the inciting antibiotic if possible 1, 3
The European Society of Clinical Microbiology and Infectious Diseases suggests considering colectomy for perforation of the colon, systemic inflammation with deteriorating clinical condition not responding to antibiotics, toxic megacolon, or severe ileus 1, 3

The European Society of Clinical Microbiology and Infectious Diseases recommends teicoplanin 100 mg twice daily as an alternative to oral vancomycin if available 1
The European Society of Clinical Microbiology and Infectious Diseases suggests fidaxomicin 200 mg twice daily for 10 days as an option for recurrent C. difficile infection 3

For patients with non-severe C. difficile colitis, the American College of Gastroenterology recommends oral metronidazole 500 mg three times daily for 10 days 5
For patients with severe C. difficile colitis, the American College of Gastroenterology recommends oral vancomycin 125 mg four times daily for 10 days 5
If oral therapy is impossible for patients with severe C. difficile colitis, the Infectious Diseases Society of America recommends IV metronidazole 500 mg three times daily PLUS intracolonic vancomycin 500 mg in 100 mL normal saline every 4-12 hours and/or vancomycin 500 mg four times daily by nasogastric tube 5, 6
For second and subsequent recurrences of C. difficile colitis, the American College of Gastroenterology recommends oral vancomycin 125 mg four times daily for at least 10 days, with consideration of a taper/pulse strategy 5, 7

The Infectious Diseases Society of America recommends discontinuing the inciting antibiotic immediately if the colitis was clearly induced by antibiotic use, particularly in mild cases 5, 6
The American College of Gastroenterology recommends avoiding antiperistaltic agents and opiates entirely as these can worsen outcomes 5, 6
The Infectious Diseases Society of America recommends considering surgical intervention (colectomy) for perforation of the colon, toxic megacolon, or severe ileus 5, 6
The American College of Gastroenterology recommends operating before serum lactate exceeds 5.0 mmol/L 5, 7

The European guidelines do not support the use of metronidazole for ulcerative colitis treatment, as evidenced by a blinded randomized controlled trial in 39 patients with acute severe ulcerative colitis, which demonstrated no benefit from metronidazole and tobramycin 8
A study suggested that metronidazole 500 mg orally three times daily for 10 days is recommended for non-severe C. difficile colitis, according to the Clinical Microbiology and Infection guidelines 9, 10

All patients with acute colitis flares should have stool testing for C. difficile to determine if metronidazole is appropriate, as recommended by the Gut guidelines 11
The Journal of Crohn's and Colitis guidelines note that always excluding C. difficile infection is crucial before concluding metronidazole is ineffective or unnecessary, especially in UC patients who have an increased risk of C. difficile co-infection 12, 11
If metronidazole is being used empirically for presumed C. difficile while awaiting test results, discontinue it immediately if C. difficile is ruled out, as continued use provides no benefit and may promote resistance, according to the Clinical Microbiology and Infection guidelines 9, 10

For severe C. difficile colitis, vancomycin is superior to metronidazole and should be used instead, as recommended by the Clinical Microbiology and Infection and Gut guidelines 9, 10, 11