LCT and hyperinsulinemic hypoglycemia, familial, 4: Currently, lactose intolerance is defined as a clinical syndrome characterized by pain and abdominal distention, flatulence, and diarrhoea that occurs after lactose consumption; this has to be distinguished from lactose maldigestion (inefficient digestion of lactose due to lactase deficiency) and malabsorption, which can also be subclinical conditions [3].