As far as foods to help soothe the stomach there are the go-tos:
BRATT (banana, rice, apple sauce, toast, tea).
Also, fresh mint, fennel, and ginger have been shown to help soothe stomach issues.
Maybe try a Blast with a banana, 1/4 cup unsweetened applesauce, a small chunk of fresh ginger (or use mint instead) and either water or brewed and chilled green tea. I haven't made this, but sounds like it may taste good. :)