 [ Symptoms ] pain shoots up my back with constipation is it endometriosis [ Disease ] no circumcision will not cause weight loss other than the weight of the foreskin that was removed but it is normal for newborns to lose a bit of weight in the first week and then gain it back to the birth weight level at the two week visit if this child has not returned to his birth weight he will need to have weekly weights and his intake monitored if he is on formula if he is breast fed and nursing well this is good nothing to worry about at this point but his weight will need to be carefully monitored if his is not gaining weight the pediatrician will take it to the next evaluative level