Doctors usually prescribe antibiotics for certain types of colitis, such as ulcerative colitis and ischemic colitis. While antibiotics help with symptoms, there may be some adverse effects.

Colitis refers to inflammation in the large intestine. There are several types of colitis, each with its own cause, such as infections or inflammatory bowel disease (IBD), the latter of which includes ulcerative colitis (UC) and Crohn’s disease.

Depending on the specific cause of the colitis, doctors may recommend antibiotic therapy as treatment.

This article examines when antibiotics are necessary to treat colitis, common prescription antibiotics, side effects, whether colitis medications are unsuitable during pregnancy, and possible drug interactions.

A person looking out the window wondering when to seek help for heart palpitations -2.Share on Pinterest
andreswd/Getty Images

Depending on the type of colitis, doctors will prescribe antibiotics. Below are the types or causes of colitis and their common treatments:

  • UC: Doctors often use antibiotics to manage IBD symptoms. These also help reduce the overactivity of the immune system that could be damaging the intestine. Antibiotics work by treating:
    • the disease itself
    • infections that arise as a complication of IBD
    • infections that arise from other treatments for IBD
  • Crohn’s disease: Doctors may prescribe antibiotics for people who develop abscesses or fistula, which are common complications of Crohn’s. They may also use antibiotics as a postsurgery measure to prevent any relapses.
  • Ischemic colitis: Doctors will consider antimicrobial therapy with broad-spectrum antibiotics for people with moderate or severe disease. A 2020 study concluded that doctors will determine the best line of treatment according to real-life clinical settings and someone’s needs.
  • Pseudomembranous colitis: This occurs as a complication of an antibiotic-associated colonic inflammation. A serious Clostridioides difficile (C.diff) infection is likely to cause pseudomembranous colitis, and treatment involves antibiotic treatment.

The common types of antibiotics vary across the type or cause of colitis someone is receiving treatment for:

Ulcerative colitis antibiotics

Depending on the type of infection requiring treatment, doctors may administer medications orally or intravenously — which involves injecting them directly into the veins. These medications can include:

Crohn’s disease antibiotics

Research from 2016 discussed the evaluation of different antibiotics in clinical trials, some of which may overlap with UC treatments, including:

  • ciprofloxacin
  • metronidazole
  • rifaximin
  • clarithromycin
  • anti-tuberculous regimens, which have a role in treating tuberculosis

Ischemic colitis antibiotics

In the previous 2020 research, doctors administered the following medications for ischemic colitis:

  • third-generation cephalosporins (Rocephin) or fluoroquinolones
  • metronidazole
  • piperacillin/tazobactam

Pseudomembranous colitis antibiotics

The Food and Drug Administration (FDA) has approved oral vancomycin and fidaxomicin to treat C. diff colitis, but metronidazole is the first-line agent.

Generally, common side effects of antibiotics may include:

More serious side effects may include infection with C. diff. This may cause diarrhea, which may lead to severe colon damage. People may also have severe allergic reactions to certain antibiotics.

If someone believes they are having an adverse reaction to an antibiotic, they need to consult a doctor.

Learn more about the side effects of antibiotics.

Specific antibiotic effects

The specific antibiotics that treat the above types of colitis may cause various side effects.

The table below shows some but not all of the side effects of common antibiotics for treating colitis:

AntibioticPossible side effects
• tendon rupture
oral thrush
• inhibited cartilage growth
• photosensitivity
QT prolongation — where the heart muscles take longer to contract and relax
gastrointestinal disturbances and possible permanent peripheral neuropathy from long-term use
no known serious adverse events, though possible drug reactions, including:
• nausea
• gastrointestinal upset
peripheral edema
• dizziness
muscle spasms
fungal or bacterial infection
vancomycingastrointestinal adverse effects of oral vancomycin:
abdominal pain
• nausea
common adverse effects of intravenous vancomycin:
• nephrotoxicity, which refers to deteriorating kidney function
• hypersensitivity reactions
• diarrhea
• gastrointestinal effects
• aortic aneurysm
• central nervous system effects
• cardiac arrhythmia
• peripheral neuropathy
retinal detachment

Some antibiotics are unsuitable for pregnant people. A person who is pregnant should consult a healthcare professional to determine the most suitable antibiotic or treatment option.

Doctors consider metronidazole safe in pregnancy in the short term. However, ciprofloxacin may cause arthropathies, which refer to arthritis, in children. Meanwhile, it is uncertain whether rifaximin is safe for pregnant people, so it is best to discuss alternative options with a medical professional.

People may need to avoid certain medications while taking specific antibiotics. Below are some examples, but it is not a comprehensive list. Other types of antibiotics may also have possible interactions with different drugs. A person should always consult a doctor before taking antibiotics.


Metronidazole may not mix well with the following:


Doctors do not recommend taking the following medications with ciprofloxacin:

Read more about the effects of ciprofloxacin.


Clarithromycin may not mix well with certain drugs. People need to inform their doctor if they are taking any of the following:

  • warfarin
  • theophylline
  • ergotamine or dihydroergotamine for migraine
  • carbamazepine or phenytoin
  • statins for lowering cholesterol, including simvastatin or atorvastatin
  • colchicine for gout
  • digoxin, for some heart problems

Doctors recommend antibiotic therapy for treating most types of colitis, including ulcerative colitis, ischemic colitis, and pseudomembranous colitis.

Two common types of antibiotics are metronidazole and ciprofloxacin. While these lines of treatment effectively reduce symptoms and maintain remission, several adverse effects have links to these antibiotics.

People may experience gastrointestinal disturbances, issues with joints and tendons, additional infections, and other side effects. A person needs to consult a doctor to determine what effects they can expect and how best to manage them.

Antibiotics may be safe for pregnant people in the short term, but they should check with their doctor before taking them. In addition, people should confirm with a healthcare professional what possible drug interactions may occur when taking antibiotics.