Gastroenteritis - Adults
What is it, exactly?
Gastroenteritis, often called a “stomach flu” or “gastro,” is an inflammation of the stomach and intestines. It often causes diarrhea (watery stools), vomiting, cramps, and sometimes fever lasting 7 days or less.
What you can do at home
What to do
- Stay hydrated by drinking small amounts frequently of an oral rehydration solution from the pharmacy (such as Pedialyte or Gastrolyte), or make a homemade solution (do not hesitate to ask your pharmacist for advice):
- 360 mL unsweetened orange juice
- 600 mL of cooled boiled water
- 2.5 mL (½ tsp) of salt
- Eat small meals and gradually increase portion sizes. Choose foods such as white pasta, rice, eggs, bread, lean meats, or unsweetened cereals.
- Wait 2 days after your diarrhea or vomiting has stopped before returning to work.
- Clean countertops, door handles, and toilets at home with a disinfectant to avoid spreading the illness to other family members.
- Wash your hands often.
- If you have a fever or pain, you may take acetaminophen (Tylenol) or ibuprofen (Advil), if appropriate for you.
Avoid
- Avoid handling other people’s food.
When to seek medical attention
If you have any of these signs:
- have signs of mild dehydration (dry mouth, excessive thirst, urinating less often, feeling weaker than usual);
- have diarrhea lasting more than 7 days;
- have a fever lasting more than 2 days, even with medication;
- have been vomiting for more than 2 consecutive days, even after following the recommendations;
- are unable to take your medication;
- take blood thinners and have had diarrhea, vomiting, or unable to eat for 1 day;
- have a weakened immune system (immunocompromised);
- developed diarrhea during or after travelling to another country.
Call 811, option 1, to speak with a nurse, or contact a healthcare professional (pharmacist, doctor, nurse practitioner).
When to go to the hospital immediately
You suddenly:
- find it harder than usual to stay awake (drowsiness);
- are less responsive to what is happening around you;
- feel confused;
- are eating and drinking less, while also having difficulty carrying out your daily activities.
You have a large amount of blood in your stool, or your stool is black.
You have severe stomach pain and a hard abdomen.
You are unable to drink or keep fluids down, despite following the recommendations.
You have diarrhea, are extremely thirsty, and have not urinated for more than 12 hours (half a day).
There is blood in your vomit.
Need help?
Call Info-Santé 811, option 1, to speak with a nurse at any time.
Consult a pharmacist for advice on medications or treatment.
Book an appointment at your medical clinic or CLSC.
If you do not have a family doctor, visit Primary Care Access Point (GAP) or dial 811, option 3.
Last update: January 1, 2026
Please note that this information does not replace the advice of a healthcare professional. If you have any concerns, please consult a healthcare professional.
References:
- Self-Care Education Nursing Guides, CIUSSS de la Capitale-Nationale
See also
See the details of Gastroenteritis
Gastroenteritis
- Infants
- Children
- Adults
- Seniors
See the details of Superficial Wound
Superficial Wound
- Infants
- Children
- Adults
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