[antonzabirko]

Definitely not the way to bet since most reactions to food are not allergic in nature. Gut reactions should constitute the majority.

[ncmncm]

You miss "anomalous". I.e., it does not happen to almost all other people who eat identically the same stuff. Indigestion and diarrhea are common responses to dietary allergens. Thus, onions make my sinuses bleed and cause indigestion.