My pre op diet Optifast was making me ill, its milk based and I am lactose intolerant,they still want me to take it just cut it down to 3 DAY and sugar free jello,thats it. I am feeling better now thank goodness! I was so sick. I am still having lot hunger pains but I am drinking water to help, can't wait to get through this phase,lol, Good luck to all:thumbup: