Several things may contribute to this. First you are doing the right thing to rinse it out, if stuff dries in there, it is really tough to clean it out. If he feels pressure after eating, this could be from gas build up, and it could force food back into the tube. You can add a few drops of simethicone to the tube before feeding. Drug stores sell this as baby gas drops in a small bottle with an eye dropper. The other is rate of feeding, and what you are describing happens more to people who use a syringe and shoot in a bolus of liquid vs those that use a bag and drip system. Also sitting up during feeding and for some time afterwards is important. Lastly, it can relate to tube placement in the stomach, which you have no control over. Ask the docs what they think, but this is probably nothing to be concerned about.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.