Analysis of gastric emptying data.

How should gastric emptying data be summarized to allow comparisons between males or between groups of subjects within a study, and to facilitate comparisons of results from study to study. We review standardization issues for reporting gastric emptying data, discuss criteria for choosing a method of analysis, review methods which have been used to describe gastric emptying data, recommend trial of the power exponential curve, and illustrate its use in the analysis and interpretation of data from several studies involving different types of meals and different types of subjects. We show why nonlinear curves should be fit using nonlinear least squares.