Could be coccidiosis. Have vet do stool sample. You dont need a visit for that. Some yogurt w/cultures meanwhile may help. Albon is used to treat coccidiosis, vet usually says 10 days, thats so you'll have to come back a time or 2.
http://www.beaglesunlimited.com/beag...occidiosis.htm
Albon 5% tastes good for 20days
http://entirelypets.stores.yahoo.net/alli516oz.html its expensive but cheaper then all the vet visits & stays good for a long time. Use as a prevenative.