Anyone who has even dabbled in eating raw living foods can tell you that there are a plethora of new bodily sensations and functions that occur, especially in the beginning and especially in the intestines. I remember when I first began making morning smoothies each day my stomach would gurgle and rumble quite loudly. I should emphasize that these sensations have never been painful - more amusing than anything. Sometimes I've felt like shouting, "IT'S ALIIIIIIIIVE!!!!" Then I realize that's precisely what's going on. I am eating living foods that have active enzymes which are doing their work.
Natalia Rose penned an animated tale of why we hear those noises and feel the rumbling in our tummies. The essay is titled "A Salad in Motion Remains in Motion" and was written for Kris Carr's blog, crazysexylife. It's definitely worth reading.
Also, if you haven't heard of Kris Carr, I recommend not only her fabulous blog, but also her amazing documentary, Crazy Sexy Cancer. Kris is full of wisdom and vitality - a sage in her 30s. Even Oprah thinks so: