OBJECTIVE The aim of this study was to investigate with Doppler sonography the variations of resistance in the superior mesenteric artery, both at fasting and in the postprandial state, in patients with celiac disease. METHODS Twenty-five patients with celiac disease (20 women, five men; mean age, 30 +/- 7 years) and 10 healthy volunteers (seven women, three men; mean age, 28 +/- 6 years) were examined with Doppler sonography. Nineteen patients were untreated (no dietary restrictions) and six patients were treated with a gluten-free diet at the time of the examination. Imaging was performed at both fasting and 15 min after an 1890-kJ meal. We introduced a parameter called "resistive difference," defined as the mathematic difference between the resistive index measured at fasting (highest value) and that measured at 15 min after the meal (lowest value) as a way to express the postprandial resistive change in the superior mesenteric artery. RESULTS Untreated patients with flat mucosa showed a resistive difference of 0.03 +/- 0.05, followed by untreated patients with mucosal subatrophy (0.05 +/- 0.04), treated patients (0.09 +/- 0.02), and healthy volunteers (0.12 +/- 0.04). A statistically significant difference was noticed between the resistive difference of healthy volunteers and both those of the untreated patients with subatrophy (p = .016) and of the patients with complete atrophy (p = .011), as well as between the resistive difference of the treated patients and both those of the untreated patients with subatrophy (p = .021) and of the patients with complete atrophy (p = .020). CONCLUSIONS We believe that Doppler measurement of resistive difference in the superior mesenteric artery can be an effective way to express severity of celiac disease and to document its regression after diet therapy.