[anonymously]

Did the veterinarian do an ultrasound/x-ray to rule out a blockage? That’s what I would have had done, going by the symptoms you describe.
Be careful reading stuff on those homeopathic sites……I find science based medicine more helpful. Supplements can cause harm.

PS: Yes, the blood test to rule out pancreatitis is important, that is how they diagnose or rule out pancreatitis. I would consider seeing an Internal Medicine Specialist and get the dog properly diagnosed as soon as possible.