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Kids Gut Health and Gastroenteritis

Robin Glicksman

Written by: Robin Glicksman

Updated: August 29th, 2023

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It’s almost back to school time— which likely means a rise in many common illnesses. Gastroenteritis is an illness that affects the digestive tract and is one of the most common diseases among school aged children. Approximately 80 percent of cases of gastroenteritis occur in the fall and winter months1. This article will take a closer look at gastroenteritis including its symptoms, how the illness is spread, and how to optimize your child’s gut health to best prevent them from getting sick.

What is gastroenteritis and what are the symptoms? 

Gastroenteritis is an illness caused by inflammation of the digestive tract. It is most commonly caused by infectious sources such as viruses, bacteria or parasitic infection but can also be caused by certain drugs or chemical toxins (e.g. lead, plant substances)2. Viruses are the most common cause of gastroenteritis accounting for 75-90% of cases3. Rotavirus was historically the most common cause of gastroenteritis in North America, but the incidence has fallen with the development of the rotavirus vaccine4. Other common viruses that cause gastroenteritis in school aged children include norovirus, astrovirus and adenovirus2. The main symptoms of gastroenteritis include nausea, vomiting, diarrhea, and belly pain. These symptoms are typically accompanied by loss of appetite, weakness, body aches and fever5. Gastroenteritis caused by a bacterial source is more likely to result in fever and bloody diarrhea2.

How do children get gastroenteritis?

The viruses that cause gastroenteritis are spread through close contact with infected persons. For example, if a child goes to the bathroom and does not wash their hands thoroughly, the virus can remain on the child’s hands and be transferred to any surfaces they touch (e.g. toys, door handles, books, etc.). If another child then touches the infected surface and puts their hands in their mouth, they can infect themselves with the virus and develop symptoms. The virus can also be spread by other forms of close contact, for example by sharing food, water, or eating utensils with someone who is infected. Bacterial gastroenteritis can be acquired by eating contaminated foods and/or drinks. Undercooked, or improperly stored meats (chicken, beef, pork) and seafood are common sources of bacterial gastroenteritis2.

Treating gastroenteritis

In most cases, viral gastroenteritis is self-limited and can be managed at home. Treatment for children includes drinking plenty of fluids to replace the fluids lost from vomiting and diarrhea6. Paracetamol can be used for fever, aches, or pains. Children with more severe symptoms may need anti-nausea medicines to control their nausea and vomiting7. Children should rest at home until the virus leaves their system given its highly contagious nature. Typically, the illness will run its course in a few days without any serious or long-lasting health effects. 

The biggest complication from gastroenteritis is dehydration because of all the diarrhea and vomiting that accompanies the illness. If a child has been vomiting excessively and/or having multiple bouts of diarrhea per day and has not been able to tolerate any food or fluids, they should be assessed by a medical professional. Moreover, if a child shows signs of dehydration, including crying with few or no tears, having a dry mouth or cracked lips, feeling dizzy or lightheaded, acting listless, irritable, or sluggish (lethargic) they should be seen urgently by a medical professional. Infants are much more likely than older children to become dehydrated and develop serious side effects8.

All infants <6 months of age with gastroenteritis should be assessed by a healthcare professional. Finally, if a child has a high fever, has blood in their stool or vomit, is vomiting for more than 24 hours or the diarrhea doesn’t get better after several days this could be a sign of bacterial gastroenteritis which requires medical assessment and, probably, antibiotics.

How can I prevent my child from getting gastroenteritis?

Good hygiene is most important to prevent spread of gastroenteritis. This includes careful hand washing, disposal of soiled clothing and proper preparation and storage of food and drinking water. It is recommended children wash their hands with soap for at least 20 seconds and water after using the restroom, after coughing or sneezing, before eating and any time they look dirty.

One common place to catch gastroenteritis is in shared food bowls, such as fruit, candy, or cookies bowls as they are handled by multiple children who might have contaminated hands. You can provide your child with individually wrapped snacks to avoid these communal bowls of food. Note that viruses can live outside the human body for prolonged periods of times.  Therefore, hard surfaces such as counters, toys and doorknobs should be disinfected with chlorine bleach-based cleaners frequently. A vaccine for rotavirus, one of the viral germs that cause gastroenteritis, exists.  Rotavirus vaccines are safe and effective in preventing and minimising harm from gastroenteritis, particularly in preventing severe disease.

Research suggests a 49–89% decline in rotavirus-associated hospital admissions and a 17–55% decline in all-cause gastroenteritis-associated hospital admissions among children younger than 5 years, within the first 2 years the vaccine was introduced10. In Canada, rotavirus vaccines are administered in infancy and are considered part of the standard immunizations of early childhood. Finally, if you or your child is sick, you can help keep others from getting sick by keeping your child home from school or staying home from work and not returning until at least 48 hours after the last symptom.  

How can I optimize my child’s digestive health?

Probiotic and prebiotic foods have the potential to improve gut health in children10. Probiotics are live microorganisms, typically bacteria or yeast, that provide health benefits to the body. They are often referred to as “good” bacteria. In children, probiotics can help maintain the healthy balance of microorganisms in the digestive system by promoting the growth of good bacteria and preventing the growth of harmful bacteria. This balance is important for digestion, nutrient absorption, and strong immune function. 

Some strains of probiotics, such as the yeast Saccharomyces boulardii and the bacteria Lactobacillus rhamnosus GG have been shown to reduce the duration and severity of symptoms in children11. Saccharomyces boulardii is an effective treatment for children with diarrhea associated with gastroenteritis andacute diarrhea. It has been shown to significantly reduce the duration of diarrhea by one day and is known to reduce the duration of vomiting in infants with acute diarrhea 12, 13.  This specific type of probiotic has the ability to attach to and interact with harmful bacteria. Additionally, it can boost the human immune system at a cellular level by encouraging the release of certain compounds like immunoglobulins. This combination of actions helps prevent harmful bacteria from flourishing in the body14

Probiotics are thought to restore the natural balance of gut bacteria that is frequently disrupted by the germs in gastroenteritis and strengthen the intestinal barrier, making it more resilient to harmful pathogens. Probiotics also produce antimicrobial substances that can directly inhibit the growth of infectious bacteria, and modulate the immune response, promoting a faster recovery. Probiotics have also been showed to be helpful for children in regulating bowel movements and reduce the frequency of constipation15. It is important to note that specific strains and dosages may vary depending on the condition and age of the child. Consulting with a healthcare professional is recommended to determine the most appropriate probiotic regimen for children.

If you’re unsure about which probiotic strain to choose, visit the Clinical Guide to Probiotic Products Available in Canada which includes a helpful list of infant probiotics for various conditions. 


  1. Elliott E, Dalby-Payne J. Gastroenteritis in children. Clin Evid2006;15:1-7.
  2. Elliott, E. J. (2007). Acute Gastroenteritis in Children. BMJ: British Medical Journal334(7583), 35–40. http://www.jstor.org/stable/20506045
  3. Dawson, Tom, Ratcliffe, Anna, Onyon, Clare. GastroenteritisPaediatrics and child health, 2022, Vol.32 (11), p.410-418 
  4. Grimwood K, Buttery JP. Clinical update: rotavirus gastroenteritis and its prevention. Lancet. 2007 Jul 28;370(9584):302-4. doi: 10.1016/S0140-6736(07)61142-8. PMID: 17662867.
  5. Graves NS. Acute gastroenteritis. Prim Care. 2013 Sep;40(3):727-41. doi: 10.1016/j.pop.2013.05.006. Epub 2013 Jul 19. PMID: 23958366; PMCID: PMC7119329.
  6. Burkhart DM. Management of acute gastroenteritis in children. Am Fam Physician. 1999 Dec;60(9):2555-63, 2565-6. Erratum in: Am Fam Physician 2000 May 1;61(9):2614. PMID: 10605991.
  7. Gavagan T, Schumann SA. This antiemetic may help kids skip that trip to the hospital. J Fam Pract. 2009 Feb;58(2):85-8. PMID: 19203492; PMCID: PMC3183922.
  8. Prisco A, Capalbo D, Guarino S, Miraglia Del Giudice E, Marzuillo P. How to interpret symptoms, signs and investigations of dehydration in children with gastroenteritis. Arch Dis Child Educ Pract Ed. 2021 Apr;106(2):114-119. doi: 10.1136/archdischild-2019-317831. Epub 2020 Jul 24. PMID: 32709593.
  9. Churgay CA, Aftab Z. Gastroenteritis in children: Part II. Prevention and management. Am Fam Physician. 2012 Jun 1;85(11):1066-70. PMID: 22962878.
  10. Bányai K, Estes MK, Martella V, Parashar UD. Viral gastroenteritis. Lancet. 2018 Jul 14;392(10142):175-186. doi: 10.1016/S0140-6736(18)31128-0. Epub 2018 Jun 29. PMID: 30025810; PMCID: PMC8883799.
  11. Depoorter L, Vandenplas Y. Probiotics in Pediatrics. A Review and Practical Guide. Nutrients. 2021 Jun 24;13(7):2176. doi: 10.3390/nu13072176. PMID: 34202742; PMCID: PMC8308463.
  12. Szajewska H, et al. 2020. Systematic review with meta-analysis: Saccharomyces boulardii for treating acute gastroenteritis in children-a 2020 update.)
  13. Burande MA, et al. 2012. Efficacy of Saccharomyces boulardii strain in acute diarrhoea in children: an Indian perspective)
  14. Stier H, Bischoff SC. Influence of Saccharomyces boulardii CNCM I-745on the gut-associated immune system. Clin Exp Gastroenterol. 2016 Sep 13;9:269-279. doi: 10.2147/CEG.S111003. PMID: 27695355; PMCID: PMC5027949.
  15. Tan T et al., “Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12®-supplemented yogurt in healthy children,” J Pediatr Gastroenterol Nutr., vol. 64, no. 2, pp. 302-309, 2018.

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