Allergic Colitis Symptoms & Causes

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We’ve provided some answers to those questions here, and when you meet with our experts, we can talk with you more about your child’s diagnosis and treatment.

What is allergic colitis?

Allergic colitis is a condition in which your baby’s immune system overreacts to the proteins found in cow’s milk, leading to inflammation and ulcerations (tiny breaks in the skin) in his colon (large intestine). Babies differ in how sensitive they are to milk. Some have very few symptoms, and others might experience blood in the stools if a breastfeeding mother has even a small splash of milk in her morning coffee.

Who is at risk for allergic colitis?

Allergic colitis isn’t uncommon — it affects between two and three percent of infants. Babies from families with a history of food allergies, asthma and/or environmental allergies seem to have a slightly higher risk of developing the condition.

Why is it a concern?

Allergic colitis can make eating very uncomfortable for your baby, so he may not get the nutrition he needs. In extremely rare cases, the intestine may get so swollen that food is unable to pass through it, or the lining of the intestine may become so inflamed that it’s unable to absorb nutrients. If this is the case with your baby, he may need to be fed intravenously (through an IV) until his intestine has had time to heal.

What complications are associated with allergic colitis?

Between ages 4 and 6 months, many babies go through a period of reflux (spitting up food), but babies with allergic colitis may have an especially hard time with reflux. This means that even though you are following a dietitian’s recommendations about how to feed your baby with allergic colitis as instructed, she may still become irritable. This doesn’t mean that her allergic reactions are back.

Medication can help your baby’s reflux until he outgrows it. This usually happens by the time he can sit up by himself, around the time he’s 7 months old.

Should I delay introducing solid foods to my child’s diet?

Not at all. Introduce solid foods just as you normally would, when your child is between 4 and 6 months old. Introducing solid foods is important because it lets your baby’s body:

  • become accustomed to new foods
  • reap the benefits of a wide variety of vitamins and minerals such as zinc and iron, found in cereal, but not in high concentrations in either breast milk or formula

Tips on introducing solid food to your child’s diet

  1. Remember to read the ingredients on the label of all baby food you buy to make sure that there’s no milk or soy (as appropriate). Make sure to do this each time you buy the food, since the recipes may change, even with your favorite brands.

  2. Introduce new foods first thing in the morning, so you can watch for an allergic reaction such as diarrhea, vomiting, rash or irritability.

  3. Introduce only one new food every three to five days, so that if your baby has a delayed allergic reaction, you know which food caused it.


What causes allergic colitis?

Allergic colitis seems to be caused by a combination of changes to the mother’s immune system during pregnancy, and the immaturity of a baby’s own immune system. But it’s not yet known why some babies develop the condition and others don’t.

There may be a hereditary component, since babies who come from families with a history of food allergies, asthma or environmental allergies seem to be more likely to have allergic colitis.


What are the symptoms of allergic colitis?

Most often, a baby with allergic colitis seems extremely fussy, difficult to console and has bloody stools. Some infants also have diarrhea and vomiting, and some may show other signs of allergies, such as nasal congestion or eczema. It’s important to remember that allergic colitis falls on a spectrum – some babies are much more sensitive to milk protein (and have much more severe symptoms) than others.


Q: How do I know if my child has allergic colitis and if I should take her to a doctor?

A: If your baby is extremely irritable, and you notice vomiting and gassiness, it’s a good idea to make an appointment to see his pediatrician. Blood in the stool is a sure sign that you should take your baby to see his doctor, who can then refer you to a pediatric gastroenterologist if it’s appropriate. Ultimately, you know your child best, and shouldn’t hesitate to contact your health care provider with any concern.

Q: Will my child be all right?

A: Yes. Allergic colitis is easily treated by removing the offending proteins from your baby’s diet.

Q: How is allergic colitis different from a milk allergy?

A: Allergic colitis is a kind of milk allergy.  But it doesn’t cause the same severe, immediate, life-threatening reaction that “regular” milk allergies cause.

Q: Is the condition ever life-threatening?

A: Only in very rare and extremely severe cases may allergic colitis be life-threatening.

Q: Will my child outgrow his allergy?

A: Most likely. The overwhelming majority of babies with allergic colitis outgrow their milk allergy by the time they’re 1 year old.

Q: Is my child more likely to develop other food allergies or gastrointestinal problems because she has allergic colitis?

A: Since infants with allergic colitis are more likely to come from families with food and/or environmental allergies, they have the same hereditary risks of future allergies that all children born to that family would have. But there’s nothing about having had allergic colitis that makes your baby more or less likely to develop another allergy or any gastrointestinal disorder.

Q: Could my child’s symptoms indicate an inflammatory bowel disorder (IBD) or irritable bowel syndrome (IBS)?

A: No. This is an understandable question, but at this age, children are too young to show any signs of either IBD or IBS — even if one or both parents have the condition.

Q: Should I delay introducing solid foods to my child’s diet?

A: Not at all. Introduce solid foods just as you normally would, when your baby is between 4 and 6 months old.

Q: Could something have happened during pregnancy to cause my baby’s allergy?

A: No. We don’t know exactly what causes allergic colitis, but we don’t think that it’s related to anything the mother did or didn’t do during her pregnancy.

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