<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hello, I had a colonoscopy this morning it all went fine but about an hour after leaving the hospital I experienced cold symptoms in the form of running nose, sneezing and tears is my left eye nose is running on the left side only as well. I had no flu or common cold symptoms prior to the colonoscopy and was wondering if the symptoms I have been experiencing the whole day since have to do with the nasal oxygen I got during the procedure ? the tube went through my left nostril an what can I do about it? Many thanks! An  <response>: Hello dear... The symptoms as mentioned in your post suggest that you might be having Allergic rhinitis, due to the oxygen tube. Management includes:1. Antihistamine preparations like Allegra can be taken for symptomatic relief.2. Montelukast, which is used as a maintenance therapy3. Maintain adequate HY Chat Doctor. 4. Also make sure that you are well protected from cold, dust other allergens. Wishing you a good health. Thanks take care. 