What causes lactose intolerance?   Lactose intolerance is often a temporary condition that can occur after a bout of gastroenteritis (stomach bug) or alongside undiagnosed coeliac disease. It can also occur in the first few months of life until the levels of lactase have become fully established (developmental lactase deficiency).   Who is affected by lactose intolerance?   Certain populations, particularly Asian and African people, suffer from a genetic form of lactose intolerance where there is a gradual loss of ability to produce lactase over time (primary lactose intolerance). Primary lactose intolerance tends to be a condition seen in older children and adults – […]