An appropriate differential diagnosis of the lymphocytic duodenosis is essential before a GFD is indicated. As a third of patients remained undiagnosed, in spite of genetic study and specific coeliac serology, flow cytometry and transglutaminase antibodies in duodenal tissue may be helpful in establishing gluten-sensitive enteropathy diagnosis. Future studies should assess whether lymphoma risk is reduced by a GFD in Marsh I patients. Also a more precise benefit in bone mineralization in this setting is needed.