It's good to know what's causing the problem.
While I was at the Vet's Office the Vet. Tech taught me how to do fecal floats. She also gave me all the info. for buying my own supplies.

Fecal Diagnostic Kit Fecalyzer, Fecal Float Device, Parasite Diagnostic - 50 Tests - Test Kits - Vet Med Direct

Fecasol- Flotation solution Fecasol Solution, 1 gallon - Test Kits - Vet Med Direct