Hi. Thanks for your query. Noted the history about your husband given potassium supplements and is now having problem of vomiting particularly after food. Potassium is known to cause gastritis locally or increase in serum potassium levels can cause many a problems. I would advise him the following: First of all, get the serum potassium, sodium and chlorides checked. Also get kidney functions done. If increased or any derangements, please get it corrected under the guidance of your Doctor. Secondly try PPI like Omeprazole and Domperidone if your Doctor suggests.