Other conditions that cause symptoms similar to food allergies include:

• Food intolerance. A food intolerance may cause similar symptoms, but they are not the result of an immune system response.
• Inflammatory bowel disease, an ongoing inflammation of the intestines that can cause abdominal pain and frequent diarrhea.
• Pyloric stenosis, a condition in babies that causes them to vomit most or all of their feedings.
• Pancreatic insufficiency, which occurs when digestive enzymes cannot leave the pancreas.
• Food poisoning, which occurs when a person eats or drinks contaminated food.
• Irritable bowel syndrome, a common digestive problem that causes episodes of abdominal pain, cramping or bloating, and diarrhea or constipation.
• Chronic idiopathic urticaria, which causes daily or almost daily raised red bumps (wheals) and itching for at least 6 weeks without a known cause.

Some medicines can cause side effects that are similar to the symptoms of food allergies.