Overview

Antibiotic-associated diarrhea refers to passing loose, watery stools three or more times a day after taking medications used to treat bacterial infections (antibiotics).

Most often, antibiotic-associated diarrhea is mild and requires no treatment. The diarrhea typically clears up within a few days after you stop taking the antibiotic. More-serious antibiotic-associated diarrhea might require stopping or switching antibiotic medications.

Symptoms

For most people, antibiotic-associated diarrhea causes mild signs and symptoms, such as:

  • Loose stools
  • More-frequent bowel movements

Antibiotic-associated diarrhea is likely to begin about a week after you start taking an antibiotic. Sometimes, however, diarrhea and other symptoms don't appear until days or even weeks after you've finished antibiotic treatment.

C. difficile infection

C. difficile is a toxin-producing bacteria that causes antibiotic-associated colitis, which can occur after the antibiotic therapy upsets the balance of good and bad bacteria in your intestinal tract.

Besides loose stools, C. difficile infection can cause:

  • Lower abdominal pain and cramping
  • Low-grade fever
  • Nausea
  • Loss of appetite

When to see a doctor

Call your doctor right away if you have serious signs and symptoms of antibiotic-associated diarrhea. These signs and symptoms are common to a number of conditions, so your doctor might recommend tests to determine the cause.

Causes

Why antibiotic-associated diarrhea occurs isn't completely understood. It's commonly thought to develop when antibacterial medications (antibiotics) upset the balance of good and bad bacteria in your gastrointestinal tract.

The antibiotics most likely to cause diarrhea

Nearly all antibiotics can cause antibiotic-associated diarrhea. Antibiotics most commonly involved include:

  • Cephalosporins, such as cefixime (Suprax) and cefpodoxime
  • Penicillins, such as amoxicillin (Amoxil, Larotid, others) and ampicillin

Risk factors

Antibiotic-associated diarrhea can occur in anyone who takes an antibiotic. But you're more likely to develop antibiotic-associated diarrhea if you:

  • Have had antibiotic-associated diarrhea in the past
  • Have taken antibiotic medications for an extended time
  • Are taking more than one antibiotic medication

Complications

One of the most common complications of any type of diarrhea is extreme loss of fluids and electrolytes (dehydration). Severe dehydration can be life-threatening. Signs and symptoms include a very dry mouth, intense thirst, little or no urination, and weakness.

Prevention

To help prevent antibiotic-associated diarrhea, try to:

  • Take antibiotics only when necessary. Don't use antibiotics unless your doctor feels they're necessary. Antibiotics can treat bacterial infections, but they won't help viral infections, such as colds and flu.
  • Ask caregivers to wash their hands. If you're hospitalized, ask everyone to wash his or her hands or use an alcohol-based hand sanitizer before touching you.
  • Tell your doctor if you've had antibiotic-associated diarrhea before. Having antibiotic-associated diarrhea once increases the chance that antibiotics will cause that same reaction again. Your doctor can select a different antibiotic for you.