Diabetic, Reconstrutive Foot Surgery, All Joints Began To Separate, Got Infection, Have Other Health Issue. Can Any Online Doctor Help?

My husband is a diabetic, has neuropathy and reconstrutive foot surgery due to osteomylenitis, which he lost of toe on the one foot and had to have reconstructive surgeryas all the joints began to seperate and the infection inthe bone shattered one of the bones. This was done last year and recently had the hardware removed and the foot is straight. Still has the ulcer that is about the size of a dime. Recently he has been having bouts with uncontrollable vomiting , can be constipated, then has diarrhea , etc. He is on insulin , had a normal EGD and colonoscopy this past week. stool cultures have been negaitve for c-diff and SSYC. No infection in the GI tract and has had the gallbladder and appendix removed. It doesn t take long when he starts vomiting that he will get dehyrated, gets IV fluids, ER can give him morphine, bentyl, zofran, phenergan, flagyl, visteral and then we are on are way home. this is now happening more frequently, last time was 10/19 and back at the ER on 10/20 and now admitted. He has been on various antibiotics, many given IV, some oral and thought that was the problem or the times that he has taken them. So he was off those and no change. Any suggestions what can cause this? Pressure on the medulla, maybe from a cyst in the brain? He is not getting any releif from the Zifran or Phenergan?