BACKGROUND In patients with functional dyspepsia (FD), tolerance to gastric fundus distension is frequently compromised. We tested the contribution of contractile cholinergic or relaxing nitrergic pathways in this disorder. METHODS Thirty-nine patients (29 women, 10 men) with FD participated in this study. Gastric distension studies where carried out by inflating a fundic balloon until the maximum distension volume (MDV) tolerated by the patient. Gastric distension was first evaluated in basal control conditions before repeating the test after the injection of anticholinergic hyoscine (Buscopan 20 mg intravenous) or following the administration of nitric oxide donor nitroglycerin (Nitrolingual 1.2 mg sublingual). RESULTS MDVs were significantly (P