Others may not become ill until several days later.
This variation matters because the last meal someone ate is not necessarily the meal responsible for the illness.
Common symptoms include abdominal cramps, nausea, diarrhea, vomiting, fever, and general fatigue.
However, several warning signs suggest that an illness may be more serious than an ordinary upset stomach.
Severe abdominal pain
Mild stomach discomfort can occur for many harmless reasons.
However, intense, persistent, or worsening abdominal pain requires medical evaluation.
It may indicate a significant infection, inflammation, or another urgent abdominal condition unrelated to food contamination.
Repeated vomiting
Vomiting becomes especially concerning when a person cannot keep liquids down.
Without sufficient fluid replacement, dehydration can develop.
This risk increases when vomiting is accompanied by diarrhea or fever.
Bloody diarrhea
Blood in the stool should not be dismissed as ordinary food poisoning.
Certain infections, including those caused by Shiga toxin-producing E. coli, can cause bloody diarrhea.
