Antibiotic Associated Diarrhea

February 6, 2017

Antibiotic Associated Diarrhea refers to a benign, self limited diarrhea following the use of antimicrobials. Studies suggest that the use of antibiotics disturbs the gastrointestinal flora resulting in symptoms like diarrhea. The major mechanisms of antibiotic-associated diarrhea (AAD) involve disturbances of the gut micro flora and the direct effects of antibiotics on the mucous membranes.

Antibiotic associated diarrhea (AAD) is a common complication of most types of antibiotics, especially for broad-spectrum antibiotics such as clindamycin, beta-lactams and 3rd generation cephalosporins. Rates of AAD vary from 5 to 39% depending upon the type of antibiotic, age, health status of the host and type of environment (hospitalization, extended care facilities, etc.). It is estimated that 10% to 15% of all hospitalized patients treated with antibiotics will develop AAD.

Antibiotics can upset the natural balance of “good” and “bad” bacteria in the intestines. Different antibiotics treat different kinds of bacteria. When an antibiotic kills one type of bacteria, other bacteria in the gut are present in greater numbers. Having too much of some kinds of bacteria in the intestines can cause diarrhea. Bacteria called Clostridium difficile (or C. difficile) are a common cause of antibiotic-associated diarrhea. They can cause severe diarrhea and an infection called pseudomembranous colitis.

Antibiotics work by destroying bacteria that makes a person ill, but they also kill good, or helpful, bacteria that are present in the intestinal system. This disrupts the delicate balance in the intestines, allowing bad intestinal bacteria that are resistant to the antibiotic to increase. Most of the time, diarrhea as an antibiotics side effect is mild and will stop on its own or when the patient will stop taking the medicine. However, antibiotic-associated diarrhea is seen a lot in patients who are hospitalized or in nursing homes. In some elderly or ill patients, diarrhea can lead to serious complications such as dehydration, a perforated colon (hole in the colon wall), or toxic megacolon, in which the colon becomes distended and could rupture.

Who is at Risk?

People who are at higher risk of developing Antibiotic-associated diarrhea when taking antibiotics include –

  • Have a history of Antibiotic-associated diarrhea
  • Over the age of 65
  • People who have had surgery on the intestinal tract
  • Certain conditions that affect the intestines – inflammatory bowel disease, Crohn’s disease, or celiac disease.


Antibiotics can upset the natural balance of “good” and “bad” bacteria in the bowel. Different antibiotics treat different kinds of bacteria. When an antibiotic kills one type of bacteria, the person then has more of other types of bacteria in the gut. Having too much of some kinds of bacteria in the gut can cause diarrhea.

Antibiotics cause diarrhea primarily through two mechanisms: the first is by diminishing or eliminating bacterial specie of the normal microflora impairing vital microbial functions such as provision of nutrient short-chain fatty acids to colonocytes and metabolism of bile acids; the second is by creating a niche for the overgrowth of intestinal pathogens including Clostridium difficile, Clostridium perfringens type A, Candida albicans, Klebsiella oxytoca, and Staphylococcus aureus.

Antibiotic-associated diarrhea include –

  • Cephalosporins – Cefixime (Suprax) and Cefpodoxime
  • Clindamycin (Cleocin)
  • Penicillins – Amoxicillin (Amoxil, Larotid) and Ampicillin
  • Esophagitisoroquinolones – Ciprofloxacin (Cipro) and Levofloxacin (Levaquin)


The main symptom of mild antibiotic-associated diarrhea is loose bowel movements or more bowel movements than normal. Antibiotic-associated diarrhea (AAD) involves occasional loose stools or mild diarrhea for several days. The problem typically begins five to 10 days after starting an antibiotic; however, in 25 to 40 percent of cases, symptoms don’t appear until up to 10 weeks after treatment ends.

Symptoms of pseudomembranous colitis are more severe and may include:

  • A lot of watery diarrhea (sometimes bloody)
  • Abdominal pain and cramping
  • Nausea
  • Dehydration
  • Fever


  • Morton’s neuroma
  • Bowel perforation – A hole in the lining of the bowel
  • Toxic megacolon – A severe condition that leads to the bowels being unable to expel gas and stool.
  • Death


Mild cases of Antibiotic-associated diarrhea often do not need any form of treatment and can be helped with home remedies. More serious cases often require treatment with antibiotics to kill the bacteria that are causing the Antibiotic-associated diarrhea.

Medications – Antibiotics are among the most frequently prescribed medications in modern medicine. Antibiotics cure disease by killing or injuring bacteria. The first antibiotic was penicillin, discovered accidentally from a mold culture. Today, over 100 different antibiotics are available to cure minor, as well as life-threatening infections. Some examples of different Antibiotic types include Penicillin, Cephalosporins, Macrolides, Esophagitisoroquinolones, Sulfonamides, Tetracyclines and Aminoglycosides.

Alternative Treatment

Probiotics – Probiotics are live organisms that are intended to provide a positive health benefit when consumed. Common strains include species of lactobacillus and bifidobacterium bacteria. Microorganisms that provide health benefits, like improved digestion ,when consumed, often found in yogurts.

Electrolytes – Correcting dehydration is critical, especially among children. Oral rehydration solutions containing sugar and electrolytes are important in managing children with dehydration from diarrheal illness.

Rice or barley water, fresh vegetable juices (especially carrot and celery), miso broth, or other clear broths help restore proper fluid and electrolyte balance.

A live yeast, Saccharomyces boulardii, is often used in Europe to prevent diarrhea associated with taking antibiotics.

Zinc may help improve immune and mucosal barrier functions.

Acupuncture – Although several studies in Traditional Chinese Medicine journals have reported success in treating childhood diarrhea, acupuncturists in the United States do not generally treat this condition in children. However, acupuncture may be used when conventional treatment has failed. In this case, acupuncturists look at both the nutritional value and the “energetic” qualities of food that might be affecting digestion.

Veratrum album – for profuse, watery diarrhea accompanied by stomach cramps, bloated abdomen, vomiting, exhaustion, and chills.

Acidophilus -acts as a mild antibiotic, which helps it to reestablish itself in the intestine, and all may aid in the production of some B vitamins and vitamin K.

Chamomile – was found to inhibit the growth of a species of bacteria called Campylobacter jejuni (one of the most common causes of enteric infections resulting in severe diarrhea).


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