Overview
Antibiotic-associated diarrhea is passing loose, watery stools three or more times a day after taking medicines called antibiotics. Antibiotics are used to treat bacterial infections.
About 1 in 5 people who take antibiotics gets antibiotic-associated diarrhea. Mild cases tend to begin shortly after taking antibiotics. Mild diarrhea usually ends after a few days on antibiotics or shortly after finishing the treatment. Diarrhea that doesn't end on its own or is more serious usually requires stopping the antibiotic. You may need to be treated with a different antibiotic.
Symptoms
For most people, antibiotic-associated diarrhea causes mild symptoms, such as:
- Loose stools.
- Passing loose stools three or more times a day.
Mild antibiotic-associated diarrhea may begin within hours or within a few days of starting an antibiotic.
Symptoms of more-serious diarrhea
Diarrhea that is more serious often begins several days to two months after starting the medicine.
Severe antibiotic-associated diarrhea happens when there is bacterial disease in the large intestine. Most often this is caused by a bacterium called Clostridioides difficile (klos-TRID-e-oi-deez dif-uh-SEEL). It is commonly called C. difficile or C. diff.
Symptoms may include:
- Frequent or severe diarrhea.
- Pain and cramping in the lower belly.
- Low fever.
- Nausea.
- Loss of appetite.
- Dehydration.
Dehydration is the loss of fluids and the minerals they carry. Symptoms of dehydration include:
- Extreme thirst or dryness in the mouth.
- Very little or no urine.
- Dark urine.
- Dizziness, lightheadedness or extreme tiredness.
- Sunken cheeks or eyes.
In young children, dehydration symptoms may include:
- No wet diapers for three or more hours.
- No tears when crying.
- A sunken soft spot in the skull.
- Unusual drowsiness.
When to see a doctor
A number of conditions can cause diarrhea. Call your healthcare professional if you have:
- Diarrhea that lasts more than two days.
- Diarrhea with belly pain, fever or other severe symptoms.
- Symptoms of dehydration.
- Stools that are black, tarry or bloody.
Causes
Antibiotic-associated diarrhea may be related to:
- Direct harm from an antibiotic to tissues of the large intestine.
- Destruction of helpful bacteria that play a role in the digestive system.
- C. difficile or other harmful bacteria that grow out of control without enough helpful bacteria to keep the harmful bacteria in check.
Antibiotics most likely to cause diarrhea
Nearly all antibiotics can cause antibiotic-associated diarrhea. Antibiotics most often involved include:
- Cephalosporins.
- Fluoroquinolones.
- Penicillins.
- Clindamycin.
- Carbapenems.
- Macrolides.
Risk factors
Antibiotic-associated diarrhea can occur in anyone who takes an antibiotic. Other risk factors include:
- Having had antibiotic-associated diarrhea in the past.
- Being an infant.
- Being 65 or older.
- Staying in a hospital for a long time.
- Living in a nursing home.
- Having a serious illness.
- Taking a medicine called a proton pump inhibitor to lower stomach acids.
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, dizziness, and weakness.
Prevention
To help prevent antibiotic-associated diarrhea:
- Take antibiotics only when needed. Don't use antibiotics unless your healthcare professional says you need them. Antibiotics can treat bacterial infections. But they won't help viral infections, such as colds and flu.
- Wash your hands frequently. Wash your hands before and after eating or meal preparation. Wash your hands after using the toilet, after handling garbage, and when your hands are clearly dirty. If you're getting care at home or in the hospital, ask all the people who care for you to wash their hands or use an alcohol-based hand sanitizer.
- Tell your healthcare professional if you've had antibiotic-associated diarrhea or C. difficile before. Having had either condition in the past increases the chance that antibiotics will cause that same reaction again. Your health professional may be able to choose a different antibiotic for you.