Ulcer present in food pipe. Can Lignocaine hydrochloride be swallowed?

Hello doctor,

My father, aged 45 years is going through chemotherapy after a major surgery in which his stomach was removed. He has Non-Hodgkin lymphoma. The medication given to him is R-CHOP. Now, it has been 9 days since his second cycle of chemotherapy and he has painful mouth ulcers, one of which is on the food pipe. Doctor has advised to use Lignocaine hydrochloride as anesthetic before eating to avoid pain. He can tolerate the pain in the mouth but when the food touches the ulcer on the food pipe, it hurts him badly. He is taking Mucaine gel for ulcer on the throat. Is there any quick solution? Can Lignocaine or Lidocaine or Xylocaine hydrochloride 2% be swallowed? Please help.

Thank you doctor,

I have just now talked to my doctor. He advised to take tablet Ultracet as a pain killer and asked to continue with Mucaine Gel. Please note, Lignocaine as anesthetic was advised by him only in case if my father was unable to consume food. He advised to swallow a small amount if sore is on food pipe.