How is he doing now? I had my gallbladder out a few years ago. I couldn't imagine not being able to take my pain meds back then. However I am all too familiar with the esophageal spasms as I suffer from them myself.
What helps me is first trying to panic. Also I drink warm temperature water and they are right, magnesium does help! You can get it in powder form as well. I used a product called Calm that you get a healt food store (Whole Foods, vitamin cottage, etc) that mixes well with water. Also I have been told that muscle relaxants have helped some.
Hope that helps too.