Just like the title says 1) Contact Purina - you can do this via live chat, email or phone call 2) Tell them that you recently bought three 31.1 pound bags of Purina Smartblend- any flavor and that there was an unusual odor coming from the bags and that they made your dog(s) have diarrhea 3) Theyll ask you where you bought them - literally anywhere will work (Walmart, Petsmart, Chewy, etc) and then theyll ask you how much you paid per a bag - say anywhere from between $25 - $30 per bag 4) Theyll offer you a refund check for the total purchase amount, just give them your information and youre all set. Your check should arrive in 3-10 days NOTE: Dont do this for over $100, otherwise theyll forward your inquiry to a supervisor and youre more likely to have problems with it