While a food allergy and a food intolerance share some of the same symptoms, they are different medical conditions. Unlike an allergy, a food intolerance involves only the digestive tract and does not trigger your immune system. Common symptoms of a food intolerance are gas and bloating after eating a certain food. While these and other symptoms can be uncomfortable, a food intolerance is not life-threatening.
Common symptoms of a food intolerance include:
- Gas and bloating
- Abdominal cramping
Common triggers of food intolerance are dairy products, corn products, and wheat and other foods that contain gluten.
While a genuine food intolerance is not life-threatening, you should see a doctor straight away if you have any of the following symptoms:
- Black and tarry stools, or diarrhoea with blood in it
- Diarrhoea on returning from a foreign country
- Diarrhoea that persists for more than two days
- Sudden constipation with stomach pain or cramping, and being unable to pass stools or gas
- A high fever (above 38℃) or a fever lasting more than 24 hours
- Nausea or vomiting that inhibits your ability to drink liquids to replace lost fluids
- Severe pain in your abdomen or rectum
Also, see a doctor straight away if you have diarrhoea accompanied by one or more of these signs of dehydration:
- Dark urine
- Dry skin
- Smaller than usual amounts of urine (or fewer wet nappies in the case of a child)
- Rapid heart rate
- Irritability and confusion
Sometimes children have a mixed reaction to a food type, and simultaneously have symptoms related to IgE (IgE refers to the antibodies called Immunoglobulin E that your body releases in the event of an allergy), such as hives or swelling, and non-IgE symptoms, such as constipation. This is common in the case of a milk allergy.