Digestive Diseases and Sciences, Vol. 36, No. I (Januao' I991), pp. 52-58 Visceral Perception in Health and Functional Dyspepsia Crossover Study of Gastric Distension with Placebo Domperidone and 9 MARC BRADETTE, MD, PIERRE PARE, MD, FRCPC, PIERRE DOUVILLE, MD, FRCPC, and ANDREE MORIN, RN The symptoms of functional dyspepsia are still unexplained. To evaluate the possible role of abnormal visceral perception, we studied the symptomatic responses and the pressure variations during progressive gastric distension in lO female healthy control subjects (mean age 33.6 years) and in lO female patients with functional dyspepsia (mean age 35.2 years). A rubber balloon was positioned 4 cm below the lower esophageal sphincter (LES) and inflated with progressively larger volumes of air by steps of 50 ml; pressures at the gastric fundus and at the LES were continuously recorded by perfused manometric catheters. Each subject was studied on two separate occasions after randomized double-blind administration of either placebo or 20 mg of domperidone. Symptomatic responses and the manometric data were analyzed at the time of the initial recognition of distension (bloating step) and at the time of reporting pain or up to a maximum of 700 ml of balloon inflation (pain or 700-ml step). On placebo, the volumes of gastric distension were more than two times lower in patients than in control subjects at the bloating step (185 +- 32 ml vs 470 +- 40 ml, P = 0.001) and at the pain or 700-ml step (265 +_ 54 ml vs 600 +- 34 ml, P < 0.005), while the pressure gradients (pressure at inflation steps minus baseline pressure before beginning inflation) were not statistically different between the two groups. On domperidone, the volumes at each of the two steps did 9 not change in comparison to results on placebo except in healthy controls at the bloating step (470 +_40 ml on placebo vs 355 +_35 ml on domperidone, P < 0.001); however, there was a trend for pressure gradients to increase on domperidone in comparison to results on placebo. We conclude that patients with functional dyspepsia have a lower threshold both to the initial symptomatic recognition and to perception of pain during gastric distension and that domperidone might have an effect on the threshold of these conscious visceral sensations. This increased visceral perception may alone or w#h other abnormalities of the gastroduo- denal tract explain the symptoms of functional dyspepsia. KEY WORDS: functional dyspepsia; essential dyspepsia; nonulcer dyspepsia; domperidone. Manuscript received June 13, 1990; revised manuscript re- ceived August 22, 1990; accepted August 30, 1990. From the Division of Gastroenterology, Department of Medi- cine, H6tel-Dieu de Qu6bec Hospital, Laval University, Qu6- bec, Canada. This study was supported in part by a grant from Janssen Pharmaceutica Inc., Canada. Address for reprint requests: Dr. Pierre Par6, H6tel-Dieu de Qu6bec, 11, C6te du Palais, Quebec, P.Q., Canada GIR 2J6. 52 Functional dyspepsia is a relatively common con- dition (1,2), and yet its cause is still unknown. The terms refer to dyspepsia in which clinical evalua- tion fails to reveal organic or structural abnormal- ities in the upper gastrointestinal tract; the syn- drome includes various symptoms of at least three months' duration, such as epigastric fullness or Digestive Diseases and Sciences, Vol. 36, No. 1 (January I991) 0163-2116/91/0100-0052506.50/0 ~f~ 1991 Plenum Publishing Corporation