The grossest of the gross are moles that have been in the pool for a few days. I cannot describe their awful, AWFUL odor. 5 and 7 at a time discovered in the leaf catcher of a Hayward Navigator pool cleaner... absolute gross-out
... and I've seen some pretty gross messes in my time.
Silently, I laugh. I keep all laughter to myself, though. As long as I've been in this business, housewives freak out when there's a dead rodent in the pool. But this one I cannot for the life of me, figure out; seems perfectly ok to allow a baby in the pool with a diaper.
If I had to choose a torture test, I'd rather swim in a pool with a dead mouse than a baby that has taken a dunk into a pool with a diaper on.
I'll throw my .2 cents in agreeing with everyone else, shock the pool. The Centers for Disease Control recommends pool superchlorination(shock) for fecal matter and a period of no swim due to the serious nature of bacterial infections and possible fatal infections for those with low immune systems.