Background and study aims:Published follow-up data on small-intestinal recovery in patients with celiac disease are scarce and contradictory.This is especially the case for adult patients,who often show incomplete histological recovery after starting a gluten-free diet(GFD) .We conducted a 2-year prospective study to evaluate the effectiveness of a GFD in improving the endoscopic and histological duodenal findings in adults with celiac disease.Patients and methods:We studied 42 consecutive adults with newly diagnosed celiac disease(13 men,29 women;mean age 32.7 years,range 15-72 years) .All the patients underwent esophagogastroduodenoscopy and small-bowel biopsy.We devised our own grading system for the endoscopic appearance of the duodenum,which ranged from “ normal” appearance to “ mild”,“ moderate”,or “ severe” alterations.Small-bowel biopsies were obtained from the second part of the duodenum(and from the duodenal bulb when it had a micronodular appearance) .The histopathological appearances were described according to modified Marsh criteria.Results:Anormal endoscopic appearance in the duodenum was found in 5/42 patients(11.9%) at entry and in 32/42 patients(76.2%) after 2 years on a GFD.Subdividing the patients according to age,patients aged from 15 years to 60 years showed significant improvement within 12 months(P< 0.0001 for patients aged from 15 years to 45 years;P< 0.003 for patients in the 46 years to 60 years group) ,whereas the improvement in endoscopic findings in patients older than 60 years was not statistically significant,even 24 months after starting the GFD.“ Normal” histology was reported in none of the patients at entry,but in 25 patients(59.5 %) after 24 months on a GFD,but this parameter did not show a significant improvement until the patients had been on the GFD for 12 months(P < 0.0001) .Only the younger patients(5-30 years) showed significant improvement of histology within 12 months(P< 0.034) ;older patients(>30 years) showed histological improvement but this was not statistically significant,even after 24 months on a GFD.Conclusions:This study shows for the first time that endoscopic recovery is faster than histological recovery in adults with celiac disease who go on a GFD.Moreover,older patients showed incomplete endoscopic and histological recovery even 24 months after starting a GFD.We therefore advise,as a minimum recommendation,that follow-up biopsies should be taken 1-2 years after starting a GFD in adults with celiac disease. Background and research aims: Published follow-up data on small-intestinal recovery in patients with celiac disease are scarce and contradictory. This is especially the case for adult patients, who often show incomplete histological recovery after starting a gluten-free diet (GFD) We conducted a 2-year prospective study to evaluate the effectiveness of a GFD in improving the endoscopic and histological duodenal findings in adults with celiac disease. Patients and methods: We studied 42 consecutive adults with newly diagnosed celiac disease (13 men, 29 women ; mean age 32.7 years, range 15-72 years). All patients underwent esophagogastroduodenoscopy and small-bowel biopsy. We devised our own grading system for the endoscopic appearance of the duodenum, which ranged from “normal” appearance to “mild” “Moderate”, or “severe” alterations. Small-bowel biopsies were obtained from the second part of the duodenum (and from the duodenal bulb when it had a micronodular appearance). His Topathological appearances were described according to modified Marsh criteria. Results: Anormal endoscopic appearance in the duodenum was found in 5/42 patients (11.9%) at entry and in 32/42 patients (76.2%) after 2 years on a GFD. Subdividing the patients according to age, patients aged from 15 years to 60 years showed significant improvement within 12 months (P <0.0001 for patients aged from 15 years to 45 years; P <0.003 for patients in the 46 years to 60 years group), the the improvement in endoscopic findings in patients older than 60 years was not quite significant, even 24 months after starting the GFD. “Normal” histology was reported in none of the patients at entry, but in 25 patients (59.5%) after 24 months on a GFD, but this parameter did not show a significant improvement until the patients had been on the GFD for 12 months (P <0.0001) .Only the younger patients (5-30 years) showed significant improvement of histology within 12 months (P <0.034 ) older patients (> 30 year.) s) showed histological improvement but this was was not significant significant, even after 24 months on a GFD. Conclusions: This study shows for the first time that endoscopic recovery is faster than histological recovery in adults with celiac disease who go on a GFD. Moreover, older patients showed incomplete endoscopic and histological recovery even 24 months after starting a GFD. We therefore advise, as a minimum recommendation, that follow-up biopsies should be taken 1-2 years after starting a GFD in adults with celiac disease.