The analysis demonstrates the utility of stochastic modeling for deriving reliable estimates of the costs associated with food-borne illness and other causes of gastrointestinal infection, while providing the most detailed and rigorous estimates to date of the associated disease- related costs in Canada. [...] The total number of respondents (4,612) and the total number of cases of gastroenteritis (391) obtained from the survey were weighted according to the distribution of the 2001 British Columbia census population (Statistics Canada) to adjust for age and sex differences between survey respondents and the general population. [...] The number of cases meeting the mild, moderate and severe definition and the total number of cases were used in a beta distribution to simulate uncertainty about the true proportion of cases that were mild, moderate and severe, respectively. [...] Table 1 shows the distribution functions of the parameters used to estimate the number of cases of gastrointestinal infection, as well as the number of cases in the defined mild, moderate, and severe categories. [...] Since two tests are used for the detection of ova and parasites, both the cost of each test and the combined cost were used in a discrete uniform distribution to simulate variability in the cost of testing.