diarrhea describes frequent, watery bowel movements (diarrhea) that
occur in response to medications used to treat bacterial infections
Most often, antibiotic-associated diarrhea is mild and clears up shortly
after stopping the antibiotic. But in some cases, antibiotic-associated
diarrhea leads to colitis, an inflammation of your colon, or a more
serious form of colitis called pseudomembranous colitis. Both can cause
abdominal pain, fever and bloody diarrhea.
Mild antibiotic-associated diarrhea may not require treatment. More
serious antibiotic-associated diarrhea may require stopping or switching
Antibiotic-associated diarrhea can cause signs and symptoms that range from mild to severe.
Common signs and 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 five to 10 days
after starting antibiotic therapy. Sometimes, however, diarrhea and
other symptoms may not appear for days or even weeks after you've
finished antibiotic treatment.
More serious signs and symptoms
Some people experience a more serious form of antibiotic-associated
diarrhea. When the overgrowth of harmful bacteria is severe, you may
have signs and symptoms of colitis or pseudomembranous colitis, such as:
* Frequent, watery diarrhea
* Abdominal pain and cramping
* Pus in your stool
* Bloody stools
When to see a doctor
Call your doctor right away if you experience signs and symptoms of
serious antibiotic-associated diarrhea. These signs and symptoms are
common to a number of conditions, so your doctor may recommend tests to
determine the cause.
Antibiotic-associated diarrhea occurs when antibacterial medications
(antibiotics) upset the balance of good and bad bacteria in your
The antibiotics most likely to cause diarrhea
Nearly all antibiotics can cause antibiotic-associated diarrhea, colitis
or pseudomembranous colitis. The antibiotics most commonly linked to
antibiotic-associated diarrhea include:
* Cephalosporins, such as cefixime (Suprax) and cefpodoxime (Vantin)
* Clindamycin (Cleocin)
* Erythromycin (Erythrocin, E.E.S., others)
* Penicillins, such as amoxicillin (Larotid, Moxatag, others) and ampicillin
* Quinolones, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin)
* Tetracyclines, such as doxycycline (Vibramycin, Periostat, others) and minocycline (Minocin, Solodyn, others)
How antibiotics cause diarrhea
Your digestive tract is a complex ecosystem that's home to millions of
microorganisms (intestinal flora), including hundreds of species of
bacteria. Many of these bacteria are beneficial, performing essential
functions. But some of the bacteria that normally inhabit your
intestinal tract are potentially dangerous. The bad bacteria are usually
kept in check by beneficial bacteria unless the delicate balance
between the two is disturbed by illness, medications or other factors.
Antibiotics can be especially disruptive to intestinal flora because
they destroy beneficial bacteria along with harmful ones. Without enough
"good" microorganisms, "bad" bacteria that are resistant to the
antibiotic you received grow out of control, producing toxins that can
damage the bowel wall and trigger inflammation.
Clostridium difficile causes most serious antibiotic-associated diarrhea
The bacterium responsible for almost all cases of pseudomembranous
colitis and many instances of severe antibiotic-associated diarrhea is
C. difficile. Most people acquire a C. difficile infection during a stay
in a hospital or nursing home after they've received antibiotics.
Antibiotic-associated diarrhea can occur in anyone who undergoes
antibiotic therapy. But you're more likely to develop
antibiotic-associated diarrhea if you:
* Previously experienced antibiotic-associated diarrhea while taking an antibiotic medication
* Are age 65 or older
* Have had surgery on your intestinal tract
* Have recently stayed in a hospital or nursing home
* Have a serious underlying illness affecting your intestines, such as colon cancer or inflammatory bowel disease
The most severe form of antibiotic-associated diarrhea, pseudomembranous
colitis, can lead to life-threatening complications, including:
* Dehydration. Severe diarrhea can lead to excessive loss of fluids
and electrolytes — essential substances such as sodium and potassium.
Extreme fluid loss can cause serious complications. Signs and symptoms
of dehydration include a very dry mouth, intense thirst, little or no
urination, and extreme weakness.
* A hole in your bowel (bowel perforation). Extensive damage to the
lining of your large intestine can lead to a perforation in the wall of
* Toxic megacolon. In this condition, your colon becomes unable to
expel gas and stool, causing it to become greatly distended (megacolon).
Signs and symptoms of toxic megacolon include abdominal pain and
swelling, fever, and weakness. Toxic megacolon is a serious complication
that can lead to infection or a ruptured colon. Toxic megacolon
requires aggressive treatment, usually with medications.
Preparing for your appointment
Start by seeing your family doctor or a general practitioner if you have
signs or symptoms of antibiotic-associated diarrhea. Your doctor will
investigate the potential causes of your signs and symptoms.
Because appointments can be brief, and because there's often a lot of
ground to cover, it's a good idea to be well prepared for your
appointment. Here's some information to help you get ready, and what to
expect from your doctor.
What you can do
* Be aware of any pre-appointment restrictions. At the time you make
the appointment, be sure to ask if there's anything you need to do in
advance, such as restrict your diet.
* Write down any symptoms you're experiencing, including any that
may seem unrelated to the reason for which you scheduled the
* Write down key personal information, including any major stresses
or recent life changes. If you've recently stayed in the hospital or in a
nursing home, include that, too.
* Make a list of all medications, as well as any vitamins or
supplements, that you're taking. If you've recently taken antibiotics,
include that information in your medications list.
* Take a family member or friend along. Sometimes it can be
difficult to absorb all the information provided during an appointment.
Someone who accompanies you may remember something that you missed or
* Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions
can help you make the most of your time together. List your questions
from most important to least important in case time runs out. For
antibiotic-associated diarrhea, some basic questions to ask your doctor
* What is likely causing my symptoms or condition?
* What are other possible causes for my symptoms or condition?
* What kinds of tests do I need?
* Is my condition likely temporary or chronic?
* What is the best course of action?
* What are the alternatives to the primary approach that you're suggesting?
* I have these other health conditions. How can I best manage them together?
* Are there any restrictions that I need to follow?
* Is there a generic alternative to the medicine you're prescribing me?
* Are there any brochures or other printed material that I can take with me? What Web sites do you recommend?
* What will determine whether I should plan for a follow-up visit?
In addition to the questions that you've prepared to ask your doctor,
don't hesitate to ask questions at any time that you don't understand
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to
answer them may allow more time later to cover other points you want to
address. Your doctor may ask:
* When did you first begin experiencing symptoms?
* Have your symptoms been continuous or occasional?
* Are you currently taking or have you recently taken antibiotics?
* Have you stayed in a hospital or nursing home recently?
What you can do in the meantime
Continue taking your antibiotics as directed by your doctor.
To cope with diarrhea until your appointment, you can:
* Drink more water and other liquids to replace fluids lost because of diarrhea.
* Eat soft, bland foods and avoid spicy or greasy foods that can aggravate diarrhea.
* Eat several small meals, rather than a few larger meals.
Tests and diagnosis
To diagnose antibiotic-associated diarrhea your doctor may:
* Ask questions about your health history. Expect your doctor to ask
about your medical history, including whether you've had recent
hospitalizations or antibiotic treatments.
* Analyze a stool sample. If your symptoms are severe, you may be
asked to provide samples of your stool. Stool samples can be tested in a
laboratory to determine which bacteria are causing your
antibiotic-associated diarrhea. This helps your doctor select the proper
Treatments and drugs
Treatment for antibiotic-associated diarrhea depends on the severity of your signs and symptoms.
Treatments to cope with mild antibiotic-associated diarrhea
If you have mild diarrhea, your symptoms may clear up within a few days
after your antibiotic treatment ends. In some cases your doctor may
advise you to stop your antibiotic therapy until your diarrhea subsides.
In the meantime, your doctor may recommend home care techniques to help
you cope with diarrhea until it resolves on its own.
Treatment to fight bad bacteria in severe antibiotic-associated diarrhea
If you experience colitis or pseudomembranous colitis, your doctor may
recommend antibiotics to kill the bad bacteria causing your
antibiotic-associated diarrhea. For many people, this antibiotic
targeted at the bad bacteria will clear up signs and symptoms. For those
with pseudomembranous colitis, diarrhea symptoms may return and require
Lifestyle and home remedies
To cope with diarrhea, try to:
* Drink plenty of fluids. Water is best, but fluids with added
sodium and potassium (electrolytes) may be beneficial as well. Try
drinking broth or watered down fruit juice. Avoid beverages that are
high in sugar or contain alcohol or caffeine, such as coffee, tea and
colas, which may aggravate your symptoms.
* Choose soft, easy-to-digest foods. These include applesauce,
bananas and rice. Avoid high-fiber foods such as beans, nuts and
vegetables. If you feel like your symptoms are improving, slowly add
high-fiber foods back to your diet.
* Try eating several small meals, rather than a few large meals.
Space meals throughout the day instead of eating two or three large
* Avoid irritating foods. Stay away from spicy, fatty or fried foods and any other foods that make your symptoms worse.
* Ask about anti-diarrheal medications. In some cases of mild
antibiotic-associated diarrhea, your doctor may recommend anti-diarrhea
medications, such as loperamide (Imodium A-D). But check with your
doctor first before taking anti-diarrheal medications because they can
interfere with your body's ability to eliminate toxins and lead to
If you're interested in trying complementary and alternative treatments
for antibiotic-associated diarrhea, discuss your options with your
doctor. One option may be probiotics — concentrated supplements of
beneficial bacteria. Probiotics are available in capsule or liquid form
and are also added to some foods, such as certain brands of yogurt.
In theory, eating a probiotic product causes good bacteria to travel to
your intestines to help boost the level of good bacteria in your
digestive tract and help defeat the bad bacteria. But there's limited
evidence to support the use of probiotics as a treatment for
antibiotic-associated diarrhea. Probiotic products contain different
strains of bacteria at varying doses. It's not clear which bacteria are
most helpful or what doses are needed.
To help prevent antibiotic-associated diarrhea, try to:
* Take antibiotics only when necessary. Limit your antibiotic use
and don't use antibiotics unless you and your doctor feel they're
absolutely necessary. For instance, 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
each person you come in contact with to wash his or her hands before
touching you. This may reduce the risk that you'll come in contact with
C. difficile, the bacterium that can cause serious antibiotic-associated
* Tell your doctor if you've experienced antibiotic-associated
diarrhea in the past. Having antibiotic-associated diarrhea once
increases the chance that antibiotics may cause that same reaction
again. Your doctor may select an antibiotic that is less likely to cause
* Consider probiotics if you've had antibiotic-associated diarrhea
in the past. Probiotics are concentrated supplements of beneficial
bacteria that you take in capsule or liquid form. Some yogurts and other
foods also contain probiotics. Some evidence suggests that taking
probiotics during antibiotic treatment may reduce the risk of diarrhea
in people who've had antibiotic-associated diarrhea caused by C.
difficile in the past. Some studies haven't found probiotics to be
useful. Ask your doctor about whether probiotics could help you.