Hi, I started having episodes exactly as you describe in January 2013..I had not even considered the sleeve at that point.. I went through extensive allergy testing which turned up nothing..they diagnosed me with idiopathic anaphylaxis..it's a severe allergic reaction to an unknown source..you get extremely tired due to a histamine overload in your intestines. I now take Zyrtec twice a day, Zantac and carry prednisone, Benadryl and an epi pen(haven't had to use that). I thought it was caused by my body rejecting the band that I had for 2 years but it has happened since I was revised to the sleeve..I hope it turns out to be something different..it is debilitating.