pop, this is kind of a puzzle. I tend to trust children when they say things about food and swallowing - but a child who can swallow bread can swallow spaghetti, in my experience.
I would go to the toddler foods jars in the grocery store and buy those for the next few weeks, and see what happens.
Has anything happened in his life in the last few weeks - a strep infection, a high fever, a move, a divorce, etc.?