You have not mentioned which was the primary problem for which Augmentin was given.
Try simple measures for now:
Light, non - greasy, non fried, non spicy food like khitchri, toasted bread, boiled potatoes, banana, cucumber, papaya in fruits, Marie arrowroot biscuits etc. Avoid too much protein for now ( like dals)
Give small meals but more frequent
At least 2 - 3 hours before sleep the dinner should be finished
You can carry on Lanszol Junior for a month too without concern for now
Next Steps
Get stool test done - routine/ microscopic and for H pylori antigen. If still not helpful we may go in for more extensive tests like food allergies, gluten intolerance
Health Tips
A home made recipe works wonders in digestion - churna made of roasted hing, jeera, ajwain and rock salt added