Hi.
Thanks for your query.
Noted the history and understood your concerns.
History of headache, stomach pains,
dark green stool and passing motion after eating is most probably indicative of an intestinal infection.
I would advise you the following in such a situation:
Get the stool tests done
Blood for CBC and liver functions along with any other tests as per the clinical evaluation.
A trial with an antibiotic active against intestinal infection,
metronidazole should help you to solve the present problem of 6 days.
Hiatus hernia not responding to
Nexium and other management needs surgical correction if the Gastro Surgeon thinks so after manometry, upper GI
Endoscopy and Barium studies.
Take soft and bland diet, plenty of oral fluids, electrolyte solution, pre and probiotics, banana and curds.