Thank you for your query,
The pains that wakes the child from sleepin is significant pain ans should be evaluated.
in lactose tolerance is uncommon.
Common causes of pain like worms, colic, urinary tract
infections to be ruled out with appropriate investigations.
abdomen is required to look for any lesions.
Physical examination is important to look for any tenderness.
So consult your Pediatrician
for the examniation and for the management.
Hope I have answered your query.