I should add that I believe I've experienced the "fish hooks" pain that you've described before. Sometimes after smoking, when I bent backwards I could feel a sharp pain in my abdomen at two spots near the bottom of my rib cage. Sometimes this pain would be aggravated just by walking. My stomach pain was never severe, what I felt was mostly bloating and feeling that my stomach contents were rising up my esophagus, but I never vomited. I also did not notice that my symptoms were eased by a hot shower. Perhaps my stomach pain wasn't severe enough for me to notice it being lessened in the shower. I don't think my symptoms match very well with CHS, but they do unfortunately stop me from smoking without discomfort.