Testing for std,s is done with a urine or swab and in the case of herpes its blood looking for antibodies.
All i can say that they have to test for specific things and if they were not requested then they would only test for the request. Why did they request a stool sample?
Yes if they tested for it. But as mentioned stool testing is more for blood for those with colon concerns.
Hi, typically stool samples are not tested for std,s and also they are from the GI track not the reproductive track so unless there was anal sex no std would show up.