Hello Thank You for contacting HCM. You having severe throat infection which is causing the symptoms. This could have been due to multiple causes like bacterial infection, irritation from drinks or diet or trauma from upper GI endoscopy. Is there history of bleeding from gum specially while brushing? Meanwhile i would suggest you following things: Take Diphenhydramine + Dextromethorphan for cough. Take hot water in a cup, add 1 table spoon salt in it. Perform gargles (mouth wash) with it three times a day for at least 3 days. It will give soothing effect. AVOID: Chilled water Drinks Spicy food Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. Wishing you good health.