Are Stomach Problems A Sign Of Food Allergies In Babies?

Some stomach problems can be a sign of food allergies in babies. But they’re usually accompanied by other symptoms. Today, we’ll break down what parents need to know about stomach problems and food allergies.

Stomach problems (GI problems), including diarrhea, constipation, abdominal pain, and gassiness, can be a sign of food allergies in babies. But they’re usually accompanied by symptoms in other areas of the body. If your baby has stomach problems, after eating certain foods, but they aren’t accompanied by other symptoms, the stomach problems may have a different cause. Today, we’ll break down what parents need to know about stomach problems and food allergies.

Stomach Problems And Food Allergies

Stomach problems can be symptoms of both main types of food allergies --- immediate-type food allergies and delayed-type food allergies.

But the way stomach problems appear is different in each type of food allergy, as we’ll break down below.

Immediate-type food allergies are also called IgE-mediated food allergies. A person with an immediate-type food allergy has an immune system that produces special antibodies to a certain food or foods --- known as IgE antibodies. IgE antibodies detect the specific proteins from foods that a person is allergic to, then trigger an allergic reaction each time the person eats those foods, to over-defend the body against the food proteins.

Immediate-type food allergies cause symptoms to appear soon after someone eats a food that they are allergic to. Usually, the symptoms will appear within seconds to minutes of eating a problem food, and almost always within two hours. Symptoms can differ from reaction to reaction.

In babies, immediate-type food allergies most commonly cause hives, or raised allergy rashes on the skin. In addition, they commonly cause vomiting, which you can learn more about in our previous article.

But they can also potentially cause certain other stomach problems: stomach pain, abdominal pain, nausea, and diarrhea. Stomach pain, nausea and abdominal pain are usually mild symptoms, where diarrhea can be a severe symptom.

Learn more about immediate-type food allergies from the NIAID:

There’s an important thing to keep in mind, though. Immediate-type food allergies don’t usually cause stomach problems on their own. These food allergies usually cause other symptoms along with the stomach problems.

Delayed-type food allergies, also called non-IgE-mediated food allergies, are much rarer than immediate-type food allergies.

They’re called “non-IgE-mediated” because they involve some sort of response from the immune system, but don’t involve IgE antibodies.

Delayed-type food allergies cause stomach problems, including stomach pain, abdominal pain, diarrhea, and vomiting, hours to days after someone eats a food that they are allergic to.

With delayed-type food allergies, stomach problems are the primary symptoms. So, stomach problems can occur on their own with delayed-type food allergies.

There are several different kinds of delayed-type food allergies.

  • One kind is known as FPIES (food protein-induced enterocolitis syndrome), which usually appears in babies. FPIES causes diarrhea and vomiting hours after someone eats a problem food.
  • Another is allergic proctocolitis, which can cause diarrhea, vomiting, and bloody or mucousy stools as a result of inflammation in the intestine.
  • A third kind is EoE, or eosinophilic esophagitis. This food allergy can cause varying symptoms, including stomach problems like abdominal pain and vomiting. It can also cause feeding problems. The main symptom is an inflamed esophagus.

Keep in mind, though, that delayed-type food allergies are very rare. So, if your baby has stomach problems after eating a food, with no other symptoms, their stomach problems are likely caused by something else (and not a food allergy).

Do constipation, gassiness, and bowel movement changes indicate a food allergy?

By itself, constipation is not a food allergy symptom.

Gassiness by itself isn’t a food allergy symptom, either.

And unless it’s diarrhea, a bowel movement change probably isn’t caused by a food allergy.

A baby who’s crying and constipated, or crying and gassy, with no other symptoms, is not experiencing a food allergy reaction. They’re having different stomach troubles.

(Wondering how to soothe your baby's constipation or gassiness? This article from Parents has great tips!)

If not a food allergy, what could be causing stomach problems?

These other common conditions could be causing your baby’s stomach problems. They are not related to food allergies.

Food Intolerance

If stomach problems (GI issues) occur on their own after baby eats a food, without other food allergy symptoms like hives, baby could have a food intolerance.

Food intolerances are completely different from food allergies, because food intolerances don’t involve the immune system. Some stomach problems that food intolerances can cause include stomach aches and pains, abdominal pain, diarrhea, gas, bloating, nausea, and vomiting.

Any food could cause symptoms of a food intolerance, but milk and soy are the most common culprits.

Remember that food intolerances and delayed-type food allergies both cause stomach problems on their own. But food intolerances are much more common than delayed-type food allergies. Immediate-type food allergies will not cause stomach problems to appear as their only symptoms.

GI symptoms, like bloating, gas, and abdominal pain, are common symptoms of food intolerance. But, these symptoms rarely occur by themselves when someone has an allergic reaction.

For more on the differences between food allergies and food intolerances, please read our linked article.

A “Stomach Bug” (Bacterial or Viral Infection)

The “stomach bug” is the common name for gastroenteritis. It causes stomach pain, diarrhea, and vomiting. In babies, this “bug” is a bacterial or viral infection. It is usually caused by the rotavirus, but could also be caused by another virus or bacteria.


Colic technically isn’t a “cause,” but a symptom. It’s used to describe any prolonged, especially loud crying that starts for no reason and can’t be soothed. But some researchers believe colicky crying is caused by stomach cramps or intestinal contractions. This may explain why colic often occurs with gas, constipation, and/or abdominal pain.

My Baby Has Stomach Problems --- Should I Stop Feeding Allergens?

Many parents wonder when to be concerned about baby’s stomach problems, especially when they’re introducing allergens to babies (including with Ready, Set Food!).

Remember that constipation, gas, or loose stools by themselves are not food allergy symptoms, even if they’re accompanied by crying. In this case, there’s no need to stop feeding Ready. Set. Food!

However, if baby starts to develop stomach or abdominal pain, has diarrhea, or vomits seconds to hours after you feed them Ready. Set. Food!, and they develop other food allergy reaction symptoms (like hives) around the same time, stop feeding Ready. Set. Food! and contact your doctor. This could likely be caused by an immediate-type food allergy.

Rest assured, though, that when food allergy reactions do occur in babies, they tend to be mild. Most babies will not have an allergic reaction when introducing a new food, and the few reactions that do occur tend to be mild or moderate.

Research led by Dr. Jonathan Spergel (Head of Allergy at Children’s Hospital of Philadelphia) has shown that the safest time to introduce allergy-causing foods is prior to baby’s first birthday.

Findings from this research have shown that:

  • Infants are the age group least likely to experience a severe allergic reaction
  • There have been no food allergy deaths in infants under the age of one
  • Food allergy reactions in infants tend to be mild, but as a child gets older, reactions increase in severity.

Also, in the three landmark clinical allergen introduction trials, there were zero severe reactions or hospitalizations among the over 2,000 infant participants.

Early allergen introduction is safe --- in fact, it’s supported by several sets of recent clinical guidelines.

Our Chief Allergist and Board Certified Allergist Katie Marks-Cogan M.D, explains how early allergen introduction is inherently safe:

If you find that baby has stomach problems like diarrhea and abdominal pain, with no other types of symptoms, but this occurs more than two hours after mealtimes, consult your doctor. This could be a sign of a food intolerance, or far more rarely, a delayed-type food allergy.

Introduce Allergens Safely and Easily with Ready. Set. Food!

All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.