Hydrogen breath test for the diagnosis of lactose intolerance, is the routine sugar load the best one?

Figure 1 Occurrence of symptoms during the HBT using 25 g lactose (HBT-25) and 12. 5 g (HBT-12.5). Some patients reported more than one symptom. It should be noted that, in HBT-12.5, minor symptoms, such as mild abdominal discomfort and abdominal distension, were reported not only by five patients with positive tests, but also by eight patients with a negative one.