If you frequently feel unwell after eating, whether it’s bloating, stomach pain, or a skin reaction, it might be more than just a sensitive stomach. Many people struggle to tell the difference between food allergies and food intolerances. Although the symptoms can seem similar, these conditions affect your body in very different ways and come with different levels of risk.
At Newtown Gastroenterology, our board-certified gastroenterologists specialize in diagnosing and treating food-related digestive issues using evidence-based methods and advanced testing. Whether you need food allergy testing or evaluation for a suspected intolerance, our team offers personalized care to help you feel better. Schedule your appointment here.
Here’s what you need to know to spot the difference and get the right care for your symptoms.
What Are Food Allergies?
A food allergy is an immune system reaction to a specific food protein. When your body mistakenly identifies a harmless food as a threat, it launches a defensive response. This can lead to symptoms that affect multiple parts of the body, including the skin, respiratory system, and gastrointestinal tract.
Common allergenic foods include:
- Peanuts and tree nuts
- Shellfish and fish
- Milk, eggs, and soy
- Wheat
Symptoms of Food Allergies
Food allergy symptoms can appear within minutes to a few hours after exposure. They may include:
- Itching or swelling in the mouth, lips, or throat
- Skin reactions like hives or eczema
- Abdominal cramps, vomiting, or diarrhea
- Coughing, wheezing, or nasal congestion
- In severe cases, anaphylaxis—a life-threatening reaction that requires emergency care
Because of these risks, food allergies must be taken seriously and diagnosed promptly.
How We Test for Food Allergies
At Newtown Gastroenterology, we offer two trusted methods for diagnosing food allergies:
- Skin Prick Test: Small amounts of suspected allergens are applied to the skin, which is then gently pricked. If a raised bump develops, it indicates an allergic response.
- Blood Test (IgE Testing): This measures the presence of immunoglobulin E (IgE) antibodies in response to specific foods. It’s ideal for patients who cannot undergo skin testing due to sensitivity or other conditions.
In some cases, our team may perform a medically supervised oral food challenge for more conclusive results.
What Are Food Intolerances?
Food intolerance is a digestive system issue, not an immune reaction. It occurs when your body has trouble breaking down certain foods, often due to enzyme deficiencies or sensitivity to certain ingredients.
Unlike allergies, food intolerances aren’t life-threatening, but they can greatly affect your quality of life and cause persistent discomfort.
Common Types of Food Intolerances
- Lactose intolerance: Inability to digest lactose, a sugar found in dairy.
- Fructose intolerance: Difficulty absorbing fructose, a sugar found in fruits, honey, and some sweeteners.
- Sucrose intolerance: Inability to digest sucrose (table sugar).
- Additive sensitivities: Reactions to preservatives, colorants, or artificial sweeteners.
Symptoms of Food Intolerance
Symptoms tend to appear gradually and are typically limited to the digestive tract:
- Gas, bloating, or abdominal discomfort
- Diarrhea or constipation
- Nausea after eating
- Headaches or fatigue (in some cases)
Though not dangerous, untreated intolerances can lead to nutrient deficiencies and chronic GI distress.
How We Test for Food Intolerances
At Newtown Gastroenterology, we use hydrogen breath testing to accurately diagnose common sugar intolerances, including lactose, fructose, and sucrose intolerance. This method is non-invasive, safe, and highly effective for identifying digestive issues related to sugar malabsorption.
How the test works:
You’ll be asked to drink a liquid containing a specific type of sugar—lactose, fructose, or sucrose. If your body has trouble breaking it down, undigested sugar ferments in the colon, producing hydrogen.
This hydrogen is absorbed into the bloodstream and eventually exhaled through the lungs. We measure hydrogen levels in your breath at regular intervals. Elevated levels indicate improper digestion and point to a specific intolerance.
Conditions we test for:
- Lactose intolerance (difficulty digesting dairy)
- Fructose intolerance (difficulty absorbing fruit sugars)
- Sucrose intolerance (difficulty digesting table sugar)
After testing, our gastroenterology team will walk you through the results and develop a customized care plan. This may include targeted dietary changes, food alternatives, and strategies to manage symptoms and improve digestive comfort.
Food Allergy vs. Food Intolerance: Key Differences
Although they can cause similar symptoms, food allergies and food intolerances involve different body systems and require different approaches to diagnosis and management. Here's a clear breakdown:
What Causes Them
- Food allergy: Triggered by an immune system overreaction to a specific food protein. Even a small amount can set off a response.
- Food intolerance: Caused by the digestive system’s inability to properly process or break down certain ingredients like lactose, fructose, or additives.
Symptoms to Watch For
- Allergy symptoms: Hives, skin rashes, swelling, wheezing, nausea, vomiting, or even anaphylaxis, a life-threatening reaction requiring immediate medical care.
- Intolerance symptoms: Mostly digestive, including bloating, gas, diarrhea, and abdominal pain. Symptoms may develop hours after eating.
When Symptoms Appear
- Allergies often produce immediate symptoms, sometimes within minutes.
- Intolerances tend to cause delayed symptoms, often several hours after the food is consumed.
Severity of Reactions
- Allergic reactions can range from mild to severe and may be life-threatening.
- Intolerances are uncomfortable but generally not dangerous or life-threatening.
Understanding these distinctions helps you avoid unnecessary food restrictions and ensures you get the right care. If you're unsure whether you're experiencing a food allergy or intolerance, our board-certified gastroenterologists can help guide you toward the right diagnosis and treatment plan.
How to Identify Your Symptoms and What to Do Next
If you think certain foods are causing uncomfortable symptoms, the first step is to track what you eat. Keep a daily log of your meals, noting:
- The types of foods you eat
- When symptoms begin and how long they last
- The specific symptoms you experience
This kind of journal can help you and your provider spot patterns. But it’s important to know that self-diagnosis is often unreliable. Food-related symptoms can overlap with other digestive conditions like IBS, celiac disease, or small intestinal bacterial overgrowth (SIBO).
That’s why we strongly recommend seeing a specialist for a proper evaluation. At Newtown Gastroenterology, our team offers accurate food allergy and intolerance testing to pinpoint the cause of your symptoms and rule out other underlying GI conditions.
With guidance from our board-certified gastroenterologists, you’ll receive a comprehensive, personalized care plan that may include:
- Professional food allergy testing near you
- Breath testing for sugar intolerances (lactose, fructose, sucrose)
- Dietary counseling to reduce symptoms without unnecessary restrictions
- Ongoing support to improve long-term digestive health
If you're experiencing recurring bloating, stomach pain, or skin reactions after eating, don’t guess, request an appointment with a gastro doctor near you and get the answers you need.
How Newtown Gastroenterology Can Help
At Newtown Gastroenterology, we specialize in helping patients find clear answers and lasting relief from food-related digestive issues. Whether you’re dealing with unexplained symptoms or have been living with discomfort for years, our team is here to provide clarity, care, and expert support every step of the way.
Our services include:
- Food allergy testing: Skin prick and IgE blood tests to identify true allergic responses
- Hydrogen breath testing: For diagnosing lactose, fructose, and sucrose intolerance in a safe, non-invasive way
- Comprehensive GI evaluation: To rule out other conditions like IBS, celiac disease, or SIBO
- Personalized treatment plans: Including medically supervised elimination diets and nutrition counseling
- Access to board-certified specialists: With decades of experience in identifying and managing complex digestive disorders
Patients choose us because we combine advanced diagnostics with personalized care, and because our board-certified gastroenterologists take the time to listen, educate, and guide every decision.
We serve patients across New York City and surrounding areas, with convenient locations and easy online appointment scheduling.
Schedule Your Food Allergy or Intolerance Test Today
Understanding how your body reacts to food is a critical step in improving your health and well-being. If you’re struggling with food allergy symptoms or think you may have a food intolerance, expert help is just a call away.
Contact Newtown Gastroenterology to schedule your food allergy or intolerance testing with our board-certified specialists. We’re here to help you feel your best every day.
