You will be unable to swallow any saliva that may accumulate in your mouth as a result of the operation. This is due to the tube being in your throat. Saliva will be suctioned from your mouth on occasion. You will also not be able to cough. There is a chance that you might swallow something while you are having endoscopy. If this happens, contact your doctor immediately. Endoscopy and other similar procedures can cause objects to be swallowed or inhaled. If this occurs, use a paper tissue to place under the nose to prevent blood from coming into contact with the instrumentation. Call your doctor or get help right away if you feel like you are choking or have trouble breathing.