Gastrointestinal lactose intolerance

Gastrointestinal lactose intolerance is the most common food-induced disorder. It is usually caused by lactase activity deficiency, and extremely rarely by glucose and galactose malabsorption. From the etiological aspect, gastrointestinal intolerance of lactose and its monomers can be primary (hereditary) and secondary, which occurs as a consequence of small intestine diseases. Primary disorders are permanent, while secondary disorders resolve with the recovery of the small intestine mucosa. This article provides a comprehensive overview of gastrointestinal lactose intolerance, both from the etiopathogenetic aspect, as well as clinical manifestations, diagnostics, and therapy.