Excellent advice for the stay. Just one other thing, remember to only work with Colby for a short time. Maybe 5 minutes several times a day. Any longer than that (for anything you're trying to teach) and they get BORED!! I would, too!

About his gas ...

What kind of food are you feeding? Have you considered changing it? Every food is not right for every dog/puppy and if he's having that much bad gas, it's probably the wrong food for his system. Millie had this little problem when we first got her and now she and Chester eat different foods. So does Aneko, but that's cause she's ancient.