Is Diarrhea Contagious? How Can Be Diarrhea Prevented?

Diarrhea may be contagious or not, depending on the cause.

Infectious diarrhea due to bacterial or parasitic food poisoning or due to rotavirus infection can be transmitted by stool-to-mouth (fecal-oral) route (with hands, water, food, toys and other objects contaminated with the stool). Additionally, viral diarrhea can be contracted by droplet infection, that is by inhaling droplets of nasal secretions or saliva of an infected and sneezing or coughing patient (usually small child).

Diarrhea is not likely to be transmitted by inhaling the odor of diarrheal stool. Diarrhea due to bacterium Clostridium dificcile or yeast Candida albicans overgrowth is not likely contracted by a healthy person, but it can be contracted by someone with lowered immunity (a person with AIDS, or a patient after antibiotic treatment, during or after chemotherapy, and so on).

Diarrhea in most of other disorders (IBS, food allergies, liver, gallbladder, pancreas disease, celiac disease, lactose intolerance, Crohn’s disease) is not likely contagious, unless the affected person develops a subsequent infection.

It is often not known why a certain person has a diarrhea, so it should be assumed that diarrhea is always contagious, even if it is not.

Prevention of Diarrhea

1. Hygiene

  • Washing hands after every contact with the stool (toilet, soil, animals)
  • Cleaning surfaces, contaminated with stool, soil, chemicals
  • Keeping small children out from daily care centers, if they have diarrhea, or if many other children have it

2. Food Preparing

  • Using clean utensils, using different pads for cutting meat and raw vegetables
  • Boiling unpasteurized milk, cooking meet until no red inside remains
  • Serving or cooling foods right after cooking

3. Disinfection of Drinking Water

  • Chlorine tablets (calcium hypochlorite) for the “point-of-use” disinfection
  • Iodine disinfection (doesn’t kill parasite cryptosporidium)
  • Water filters with label ‘reverse osmosis’ and pores smaller than 1 micron, may protect against all microbes, but they are expensive and easily plugged with particles of dirt. Cheaper filters should be used in combination with chemical disinfection or boiling (1)
  • Chlorine bleach (sodium hypochlorite) for wells, pools, water supplies

4. Drugs

Antibiotics are not generally recommended as a prevention of diarrhea, because of their many side effects and possible development of bacterial resistance. They can be prescribed to people with lowered immunity, or for important travel for the short term use (they are effective in most cases). Pepto-Bismol, chewable tablets 4 times a day (with meals and in the evening), may prevent bacterial diarrhea in some cases (2). The drug should not be taken more than 3 weeks in a row.

5. Vaccination

Rotavirus vaccine Rotateq (in US and Canada) or Rotarix (in Europe) is recommended for children under 5 years of age (routinely performed together with other vaccines in infants). Vaccinations have no known serious side effects, and they are effective in over 70% of cases.

Measles + Mumps + Rubella + Varicella (MMRV), Hepatitis A, and Typhoid vaccine are recommended for children older than one year, before a travel to risky countries. Yellow fever vaccine is required for a travel to some African and South American countries.

Vaccination of Animals:

  • Salmonella vaccine for poultry (3);
  • E. coli 0157:H7 vaccine for cattle; available in Canada (4);
  • Entamoeba histolytica vaccine for cattle (5).

6. Foods to Stop Diarrhea

When diarrhea has already started, there is no special diet to stop it. All foods from BRAT diet (Bananas, Rice, Apple sauce, Toast) are appropriate in most cases of acute diarrhea, but other foods may be also fine. An usual diet is recommended – one should eat as he/she feels comfortable, unless a certain food was recognized as a cause of diarrhea. Heavy sugary or fatty foods should be avoided in all cases of diarrhea, though.

A person with diarrhea should replace lost fluid, so regular drinking is a must. Drinks, sweetened with sorbitol or HFCS, or large amounts of fruit juices can cause loose stools even in healthy persons, so they should be avoided in diarrhea. Plain water or, in heavy diarrhea, rehydration solutions, like Rehydralyte, are appropriate.

Related Articles:


  1. Water disinfection  (
  2. Prevention of diarrhea, Pepto-Bismol  (
  3. Salmonella vaccine  (
  4. E.coli vaccine for cattle  (
  5. Entamoeba vaccine  (
About Jan Modric (249 Articles)
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