You have descibed your unfortunate experience of Post-Operative-Nausea and Vomiting (PONV) very clearly. It was obviously miserable for you. PONV is a condition that we all take very seriously. We employ an variety of drugs with anti-sickness activity to mitigate PONV, however sometimes, despite our best efforts it still occurs. Unfortunately some patients seem to be susceptible to PONV when others won't be. PONV is often mutifactorial dependent on the nature of the operation, smoking status, existing medical condions and strong pain relieving drugs. I am confident that a true severe allergic reaction which would most likely have manifested with specific and characteristic signs would have ben identified during your stay in hospital. I would encourage you to highlight your previous experience of PONV if you were to attend hospital in the future, when additional measures could be taken to try to reduce the liklihood of this unfortunate consequence of having an operation.