It’s normal to sometimes experience uncomfortable gastrointestinal symptoms like bloating, gas, constipation, and diarrhea. But if you frequently have GI issues, you may have a food allergy, intolerance, or sensitivity.
The biggest difference between a food intolerance and an allergy is that an intolerance is related to your digestive system, while an allergy is related to the immune system. Typically, food intolerance symptoms are milder than food allergy symptoms.
What is a food allergy?
A food allergy is an immune system response to a certain trigger. The body sees that particular food as a threat. The most common food allergens are:
- Wheat
- Eggs
- Soy
- Milk
- Shellfish
- Fish
- Peanuts
- Tree nuts (like cashews and walnuts)
Food allergies can potentially be severe or life-threatening, even if you’re only exposed to a small amount of the allergen. Symptoms usually occur within two hours of exposure and can include:
- Trouble breathing
- Wheezing
- Difficulty swallowing
- Vomiting
- Diarrhea
- Rash or hives
- Swelling of the lips, tongue or throat
- Anaphylaxis, a serious reaction that causes dizziness, trouble breathing and loss of consciousness
If you have a known food allergy, you should always keep an epinephrine autoinjector (like an EpiPen) with you. Anaphylaxis can be fatal if not treated immediately with epinephrine and professional medical care.
What is a food intolerance?
A food intolerance is a digestive tract issue where your body has difficulty breaking down certain foods or preservatives. A common example is lactose intolerance, where the body has difficulty digesting lactose, a sugar found in milk products.
Food intolerance symptoms can cause discomfort but aren’t usually severe or life-threatening. They can include:
- Bloating
- Gas
- Heartburn
- Diarrhea
- Stomach pain
- Nausea
Over-the-counter medications for lactose intolerance can help reduce mild symptoms.
Is celiac disease a food allergy?
Celiac disease isn’t a food allergy, but an autoimmune disorder triggered by gluten. If you have celiac disease, consuming even a small amount of gluten can cause damage to your GI tract.
There are also people who don’t have celiac disease, but have a gluten intolerance, which causes gas, bloating and fatigue.
What is a food sensitivity?
In addition to food allergies and intolerances, there are also food sensitivities. Like a food allergy, a food sensitivity is caused by an immune response, though symptoms are generally mild. A food sensitivity can be related to an imbalance of your gut bacteria.
Symptoms of a food sensitivity can take several days to appear and include:
- Brain fog
- Headaches or migraines
- Itching
- Stuffy or runny nose
- Sneezing
- Joint pain
- Muscle pain
What causes food allergies?
Allergies and intolerances can be genetic or develop over time. While more research is needed, studies indicate children may be more likely to have a food allergy if one or both parents have a food allergy.
When to seek medical care
If you experience any of the symptoms mentioned above, talk to your primary care provider. They may:
- Ask you to keep a food diary to identify potential triggers.
- Recommend a short-term elimination diet.
- Refer you for allergy testing.
If you experience a severe allergic reaction, use your epinephrine autoinjector and seek emergency medical care. Find a provider near you at pardeehospital.org.
