What can ruin a stool specimen if it is included?

Including urine in a stool specimen can indeed compromise the integrity of the sample. Urine can introduce bacteria and other substances that can alter the results of the analysis. Stool specimens are often examined for the presence of pathogens, blood, or other indicators of gastrointestinal conditions. When urine contaminates the stool, it can lead to false positives or negatives, rendering the results unreliable.

On the other hand, liquid stool, hard stool, or an excessively large quantity of stool usually would not jeopardize the basic capability of the sample to be tested, although they might affect how well the sample can be analyzed or the interpretation of the results. Proper collection methods are essential to ensure accurate testing outcomes, and preventing contamination by substances like urine is a key part of maintaining the quality of the specimen.