Some people have food intolerances or allergies that cause negative reactions when consuming certain foods. There are several types of food intolerances including enzyme deficiencies that prevent proper digestion, malabsorption issues that impair nutrient absorption, and allergic reactions from the immune system. Coeliac disease is an autoimmune reaction to gluten that damages the small intestine lining. Managing food intolerances requires identifying the specific intolerance and following dietary guidelines developed by a dietitian to avoid problematic foods.