Thanks for your query.
Noted the history and understood the concerns.
Intermittent stomach pains, bloating, diarrhea
and vomiting indicate that you and your wife have gastroenteritis
or food poisoning
and surely there may be some problem at your Mothers water or food source.
Well, ask your Mother whether anyone there too suffer from similar symptoms?
I would advise you the following in such a situation:
Get stool and blood tests done.
Get a course of an antibiotic, metronidazole
Take coiled and cooled water, homemade fresh foods.
Take plenty of oral fluids and electrolyte solution to have proper hydration and electrolyte balance.
If the symptoms increase or do not come under control you may need an admission to the hospital for intravenous fluids and antibiotics.