No improvement?/ His belly is still swollen?? Any lessening, any signs of improvement?
I would try the peas or anything with a fiber component (veg flakes work too). As for preping the peas, I'm not sure just mic them for a minute and let cool. That should prolly be okay. Popping them would prolly be a good idea too to help them break through the skin.
Try this, see if he eats.