Symptoms of food poisoning are caused by toxins present in the contaminated food or water. The severity of the symptoms is directly related to the concentration of the toxins in the contaminated food or water. This means that eating a lot of weakly contaminated food can be just as bad as eating as eating a small amount of heavily contaminated food.

Symptoms of food poisoning usually develop within 6 hours of eating the contaminated food. In some cases, the symptoms may not develop for 48 hours.

Symptoms of food poisoning include:

• Cramping abdominal pain
• Diarrhea
• Nausea
• Vomiting

Less common symptoms of food poisoning include:

• Fever
• Bloody stool
• Stool that contains mucus or pus

Loss of fluids from diarrhea may lead to dehydration.

Symptoms of dehydration include:

• Decreased urination
• Urine is darker than usual
• Faintness
• Dry mouth
• Dry skin
• Fainting
• Nausea
• Excessive thirst
• Weakness or fatigue
• Unintentional weight loss
• Rapid pulse