The phrase "poured in" can be replaced with a variety of synonyms depending on the context. Some possible synonyms include flooded, inundated, deluged, swarmed, rushed, streamed, or gushed in. For example, if describing a large number of people entering a concert venue, one might say they flooded in. If describing rain during a storm, one might say it deluged the streets. If describing a sudden influx of customers at a store, one might say they swarmed in. Using synonyms can add variety and interest to writing, as well as more accurately convey the intended meaning.