Since you are pre-WLS I don't think you have the foamies. Foamies happen when you eat too much or too fast and fill/overfill your pouch. When the pouch fills it gets really uncomfortable and your body starts producing lots of saliva to try to wash everything down. Since the pouch is full, there isn't any place for this saliva to go. Imagine what happens, you spit or regurgiatate it back up. Really unpleasant. Just like dumping, this becomes a good deterrant to eat only what you can stomach (literally). I've have the foamies several times (must eat slow) and they resolved within 30-60 minutes.
Folks suggest the meat tenderizer or papaya enzyme to break down meat that gets stuck in the pouch, I suppose that could lead to foamies too I suppose (chew your food really well).
Hope this helps.