Many people are sensitive or allergic to lactose in milk or gluten in wheat, rye and barley. Dietary awareness, and a myriad of gluten-free, lactose-free products, offer a line of defense.

Celiac disease is an autoimmune disorder. The severity of this food intolerance, or allergic reactions to certains foods, varies from mild to potentially life threatening.

In people with celiac disease, the immune system launches attacks against the small intestine when gluten is present. These attacks damage the intestinal lining and prevent nutrients from being properly absorbed.

Celiac disease symptoms include diarrhea, vomiting, abdominal pain, and constipation. People with celiac disease must go on a gluten-free diet, avoiding all foods containing gluten, such as white flour, wheat flour, wheat germ, wheat bran, graham flour, semolina, and spelt.

Gluten intolerance is a catchall term that refers to people with all levels of sensitivity to gluten—including celiac disease, non-celiac gluten sensitivity, and wheat allergy. People with non-celiac gluten sensitivity develop symptoms like stomach upset, but damage is not occurring in their intestines. Wheat allergy is an immune system reaction to foods containing wheat. Gluten intolerance symptoms range from stomach upset to hives, a rash, congestion, and difficulty breathing.

People with lactose intolerance do not have enough of the lactase enzyme needed to properly digest lactose—the sugar found in milk. As a result, when they eat dairy products, they develop unpleasant symptoms such as bloating, gas, and diarrhea. Avoiding dairy products is one way to prevent these symptoms. People who still want to eat dairy can take a pill that contains lactase, or choose dairy products that have already had the lactose broken down.