Hello good afternoon mam,
First n foremost I would like to jot down the concerns here.
1)Acne -back thigh to knee.
2)1.8yr old and jus 8kgs
3)Need to poop after every meal.
Acne or skin lesions I would like to comment only if I could observe n examine.
Her weight for age it not apt n moreover if less than 50th percentile (trying to tell she s among those 50 kids out of 100whose should have been normal)
Urge to defecate after meal is normal for infants till they are toddlers(Upto the years )
It's called gastro-colic reflex,which Is completely physiological (normal)
Next Steps
visit a dermatologist after a pediatrician s reference for overall examination and to tile out other things for failure to thrive
Health Tips
to be careful not to get secondary skin infection from acnes by maintaining good hygeine