I’ve interspersed what stands up in the case for the options available for this question:
Liver and Stomach Qi Stagnation
There are a couple of symptoms thrown in here to kind of throw you off – Wiry pulse (can indicate Liver-Qi Stagnation or pain), and internal vexation. However, there are no other symptoms, so we can’t go too far down that rabbit hole.
Cold fluid blocking the middle jiao
There’s something blocking the Middle Jiao because he has frequent nausea, occasional vomitus, belching, and a feeling of palpitations in the abdomen. The things that stand out are: cold (indicating Cold), a wet and puffy tongue (this indicates Cold, but is starting to point me in the direction of an internal Cold condition likely due to a Yang Deficiency of some sort), and a tight pulse (Cold).
Liver and Stomach Yang Deficiency
This is a funny ditty of a diagnosis. Liver-what? The Liver is generally only deficient in Blood and/or Yin. Neither of theses are present so this answer gets scrapped.
Spleen and Kidney Yang Deficiency, Cold fluid blocking the middle jiao
This seems the most plausible. We’ve found there to be cold, there’s something blocking the Middle Jiao, and there seems to be a Yang Deficiency (plus back pain! which indicates a Kidney thing!).
Spleen and Stomach Yang Deficiency, Damp blocking the middle jiao
So why is there not overt Dampness? The tongue is puffy, right? But puffy could indicate that it’s swollen, which points to Spleen Deficiency, not specifically Dampness. And look at that coating! The tongue coating is white. Not thick-white. Normal. The pulse? Not slippery. I think we can safely rule out Dampness.
This one is tricky. We really have to look at all the signs and symptoms and make a case for what we’re choosing.