Figure 1.

Consort flow-chart of screened patients. Starting from a general group of 135 symptomatic patients, and after exclusion of 21 patients with organic diseases, a subgroup of 114 patients had functional gastrointestinal symptoms. After further exclusions of 15 patients with Rome IV criteria, 99 patients underwent lactose H2 breath test and 75 were lactose intolerant, of which 34 had persisting symptoms following a lactose-free diet for at least six months, and were enrolled. Following the refusal of 11 subjects, the final study group consisted of 23 patients.