+1 to the floating hide. I am used to fighting swim bladder issues with tiger barbs, and they would never use a hide...
You won't see him releasing the gas as bubbles, those are likely bubbles from gulping air at the surface. I also recommend against rubbing its belly, no matter how gently, since there is no direct vent to release the gas from the bladder to the outside of the fish. It is a physiological process that occurs in a specialized organ called the rete mirabile, which will diffuse the gas back into the bloodstream. Rubbing its belly will just further stress a sick fish. It is likely an infection that is impeeding the proper function of the rete mirabile, and the salt should help that. You can use 1.5" foam core PVC pipe, labelled 'for drian, waste and vent only'. Air is blown into the PVC pipe wall as it is extruded to reduce the amount of plastic used, weakens the pipe so not good for pressure applications so they only make it in drain sizes. Foam core pipe floats, and I think that Lowes sells it in sections as short as 2 feet, easy to cut, and you can probably cut it in the store.
Not likely, this seems to be swim bladder issues, not intestinal, peas act as a laxative which aids intestinal issues
