Most straightforward gastro (“stomach bug” / gastroenteritis) cases last around 1–3 days , but symptoms can hang around for up to a week, and in some cases up to 2 weeks depending on the cause.

Typical duration

  • Viral gastro (most common):
    • Nausea, vomiting and watery diarrhoea usually peak over 1–3 days.
* Some people feel washed out, with loose stools or mild cramps, for **up to a week**.
  • Bacterial or more severe infections:
    • Can last longer , often over a week , and sometimes up to 2 weeks or more , especially if there are complications or you need antibiotics.
  • Medical definitions:
    • “Acute” gastroenteritis: symptoms up to 14 days.
* “Persistent”: **14–30 days** ; “chronic”: more than **30 days** (these are less common and need medical review).

When to worry about how long it’s lasting

See a doctor or urgent care now (or emergency if severe) if:

  • Symptoms last more than 5–7 days with no real improvement, or suddenly get worse again.
  • You cannot keep down fluids for more than 24 hours , or you are vomiting repeatedly.
  • There are signs of dehydration : very dry mouth, no tears, little or no urine, dark urine, dizziness, confusion or feeling faint.
  • You have blood in vomit or stool, high fever, or severe stomach pain.
  • You are pregnant, elderly, very young (baby/child) , or have long-term conditions (kidney disease, diabetes, immune problems, heart disease). These groups can get very sick from dehydration more quickly.

If symptoms are slowly improving over a few days, you can usually care for it at home with fluids, rest and simple foods, but any red-flag sign is a reason to seek urgent advice.

Information gathered from public forums or data available on the internet and portrayed here.