Unfortunately this site does not permit us to make serious, informative posts on complex subjects as it is impossible to upload a series of supporting, explanatory illustrations.
Several members have expressed an interest in furthering their understanding of reflux and the mechanics and remedies associated with it.
I will endeavor to present further information in the form of 'snippets' which can be understood with only a single visual aid.
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This simplified (!) diagram outlines the systems by which the stomach produces digestive acid (HCL) on demand, as well as Pepsin (an enzyme for protein digestion) and intrinsic co-factor ( a chaperone for Vitamin B12).
This is an extraordinarily complex process involving feed-back loops of several stimuli from several sources.
Now factor in the cutting of part or all of the Vagus nerves communicating with the stomach and the surgical removal of significant areas of the stomach wall as part of the surgeons efforts to fabricate the new stomach-gullet tube, with adequate margins away from any cancerous tissue.
Also bear in mind that these disruptive changes will be different in every single patient.
Is it any wonder that this is so difficult a problem to wrestle with?