New York-based internist and gastroenterologist Dr. Niket Sonpal told Well+Good, “Typically, if you ingest enough spoiled milk, it can take a toll on your gastrointestinal tract.” We’re talking stomach cramps, vomiting, and diarrhea. The effects of ingesting more than a sip of spoiled milk are similar to the effects of consuming other foods that carry food-borne illnesses, per Missouri Poison Center. Most of the time, the after-effects of eating or drinking something spoiled should resolve on their own, though you might have to wait 12 to 24 hours.
The first thing you should do if you think you have food poisoning is to replenish lost fluids from all the vomiting and diarrhea. Aim to hydrate with beverages that have sugar and electrolytes, per Missouri Poison Center. Avoid taking any medications without a doctor’s approval. If your symptoms don’t improve within 24 hours, if you’re severely dehydrated and vomiting everything you take in, if you have a fever, and if your diarrhea continues for more than three days, it’s time to visit your healthcare provider, noted the Centers for Disease Control and Prevention. It might be wise to prevent this from happening by storing your milk the proper way and also by understanding how milk spoils in the first place.