HI, thanks for using healthcare magic
Pain in the left lower side of the abdomen is usually related to the bowels.
Pain on the right would be associated with the risk of
appendicitis.
It is possible that he may have food
poisoning, it would be best to avoid any further
dosing of the
magnesium supplement because this would worsen his symptoms.
Though food poisoning is a possibility,
abdominal pain is best diagnosed when the abdomen is examined, he may need to be seen
If it is food poisoning then treatment would consist of --(1) holding off solids till there is a 4 hour period with no symptoms
(2)fluids and electrolyte replacement
(3)probiotics help shorten the course
(4)when restarting eating use small amount of dry solid foods initially
I hope this helps