I think the type of bag depends on where in the colon the stoma comes from. If you've got a lot of your colon, the stool can be almost formed, and draining it would be very difficult. If his stool is of a consistency that can be drained, it's probably up to him whether we wants to use drainable pouches.
When the output is thicker, it does stay up at the top. My nurse told me to blow into the bag, but they do sell gels and lubricants you can put into the bag, that might work better than baby oil since they are designed for that purpose:
www.hollister.com/en/products/Ostomy-Care-Products/Ostomy-Accessories/Lubricating-Deodorant/Adapt-Lubricating-DeodorantI think if I were in his shoes, regardless of whether I was using an
open or closed end bag, I would consider getting a two piece system. At least then, when you empty, you don't have to change the wafer. With the snap on, you just snap one off, and snap another on. It's much easier than messing with the adhesive remover and barrier protector multiple times a day.
Take a look here:
http://www.hollister.com/en/products/ostomy-care-products/ceraplus?s=Relevance&pg=1Those have snap systems.