Abstract: A method is disclosed for determining the presence or amount of analyte in a fecal sample. The method comprises the steps of (A) contacting the fecal sample with an extraction reagent comprised of at least one detergent and at least one buffer to form a mixture, (B) applying the mixture to an absorbent filter that is in proximity to or in contact with an immunoassay such that analyte present in the sample is transferred to the immunoassay, and (C) detecting the presence of analyte by said immunoassay. In a preferred embodiment, the immunoassay comprises a porous strip containing immunoreagents for detecting analyte.