Thank you Mike for the comprehensive reply :-) I actually know of a good enteral formula my environmental doc suggested to me, and I have used (but not for 10 days or more but I may give that a try soon thanks to you and the OP)--its called Vivonex Plus and you can order from Walgreens pharmacy online. It has 300 calories per packet, it's expensive and tastes like hell (drinking it with long straws aimed at the back of your throat helps), but it is packed with easily absorbed nutrition.