Would vistaril work as well as phenergan (promethazine) for vomiting associated with gastroenteritis?

Can work here...: Vistaril (hydroxyzine) reduces activity in the central nervous system. It acts as an antihistamine to address sneezing ; runny nose, as well as hives on the skin. Vistaril is also used as a sedative to treat anxiety ; as an adjunct for anesthesia. Vistaril may also be used to treat nausea ; vomiting. Watch out for sleepiness with this drug ; don't combine it with other sedative agents.

Likely not: Phenergan (promethazine) is more sedating but more effective on vomiting. Vistaril does not have much if any anti-emetic action.