The thought behind drinking Gatorade is correct (electrolytes), but the sugar in Gatorade makes diarrhea worse. You could try either Pedialyte (make sure it's very cold because it doesn't taste very good) or the Pedialyte ice pops. Also, (and I apologize if someone already mentioned this) have you tried the BRAT diet for a few days? It's basically ripe bananas (not green), plain rice, applesauce (but not apple juice), and dry toast (no butter, jam, etc.). The BRAT diet usually solidifies stools that are loose for whatever reason. Then, if your symptoms improve, slowly reintroduce other foods, leaving raw fruits and veggies, spicy foods, sugary foods, and fats for last. Just work through the progression of bland. It's not much fun, but it helps. Also, are you taking prenatal vitamins? The amount of iron in them can be very tough on the stomach. You could ask your OB if it's okay to switch to one w/out iron for the next couple of weeks. I wasn't able to use vitamins w/ iron at all when I was pregnant, and my OB just kept good track of my iron levels.
The good news, as you probably already now, is that you are already full-term. While docs use 40 weeks for your due date, they consider the baby to be full term by 37 weeks. I hope you feel better soon!