Both food allergies and food intolerance can cause gastrointestinal symptoms such as stomach cramps and diarrhea. To know which you are experiencing, identify which parts or your body are involved. Since food allergies may be life-threatening, it's critical to identify whether your stomach cramps and diarrhea are associated with a food that you have difficulty digesting or if it's a food to which you are allergic.
Food Allergy
A food allergy is a bodily response to just a small amount of the allergen. It typically involves multiple parts of your body, from skin that breaks out in a rash or hives to a runny nose and cough from excess mucus. The response is typically immediate to the presence of the allergen when ingested or even inhaled. Stomach cramps, diarrhea, nausea and vomiting may also accompany an allergy, which is why it is often confusing to identify.
Food Intolerance
A food intolerance is typically limited to digestive problems. You may have stomach cramps, diarrhea, vomiting and nausea, but you don't have a runny nose, hives, a rash or any swelling. In addition, a food intolerance doesn't occur immediately and isn't usually severe. And, in some cases, you can eat some of the food to which you are intolerant, but if you eat too much, your body manifests symptoms that are limited to gastrointestinal distress.
Identifying the Difference
If you suspect you have a food allergy, contact your doctor. With allergies, severe, life-threatening reactions may occur. Your doctor will order tests -- either a pin-prick test to identify if you respond to the introduction of an allergen, or a blood test. Once diagnosed, your doctor will identify the best treatment options. For some, this means carrying antihistamines. For others, you need to carry epinephrine in the form of an automatic-injection pen to stop a life-threatening anaphylactic shock reaction.
Considerations
If you're uncertain about your gut's response to some foods, the most definitive test is a food challenge test. A skin-prick test may not give a clear results, and blood tests are not as conclusive, according to an article on allergy tests and false results printed in "The New York Times" in May 2010. In a food challenge test, you are given foods and a placebo. If you respond to the food in question, you are allergic. The test is time-consuming, but it provides conclusive results.
