Stomach rumbling at night after new diet + workout routine?

I recently made some changes to my diet (eating raw vegetables, lean protein, complex carbohydrates etc) and my exercise routine (HIIT every other day accompanied by steady cardio/basic weight training exercises). I'm fine during the day but the instant I try to get some sleep, my stomach starts feeling twitchy and rumbly. Basically, it feels like I've had a whole bunch of coffee. I'm positive that it's not hunger pain, and I've made sure to stay hydrated. This is keeping me up at night and I don't know what to do!