Hi, thanks for using healthcare magic
It is possible that there is mild inflammation to the esophagus
due to this trauma. This would cause discomfort on eating.
He may want to avoid hot/spicy/ acidic foods that may aggravate the area and slow down healing.
In addition the use of anti inflammatory pain killers such as ibuprofen/cataflam/naproxen/aspirin
would be helpful.
I hope this helps