I have checked all the definition entries for the words percolation and gastric, yet I can't totally understand what "gastric percolation" means in the following sentence:
Of more urgent concern is the gastric percolation that I am experiencing [Reference].
Does it mean fullness of the stomach? That's the only meaningful interpretation that I can come up according to the dictionary entries.
In this context, gastric percolation means "the filtering through the stomach" and he is using it to mean he has diarrhoea.
The writing is describing it very delicately, but the link shows key words "continence", "sputtering" and "toilet paper". "Could I get sick from a tiny residue of bad water?"
"Gastric percolation" is simply a colorful way to describe his abdominal discomfort due to persistent diarrhea. We can imagine he feels an internal sensation akin to the sound of percolating coffee -- a constant -- and increasingly urgent -- bubbling and rumbling in his belly.
Anatomically speaking, this is actually happening in the author's colon, not his stomach, so it should be colonic or intestinal percolation. Gastric specifically refers to the stomach, not the entire digestive system ... but I suppose we can forgive the author's lack of medical accuracy.
