underweight toddler

My daughter is 3 1/2 and has weighed between 28 and 30 pds. for the past year and a half. She had viscoueretral reflux and was on antibiotics for two years but has been off of it for a year now due to numerous surgeries to fix the problem. It concerns me that she has not gained much weight this whole time. I had heard we can give her protein shakes and I was wondering if this would be a bad idea due to her previous kidney problems?

[Renee Radenberg]

Her weight is on the 25th percentile and her height is between 10-25th percentile for her age. She may not have gained but she had not lost weight either which is good considering what she has been through with surgery and numerous infections this past year. Does she have kidney damage from the viscoueretral reflux (VUR) and following a low protein special diet? If not, then she can have milkshakes. If she is following a special diet, there are drinks with extra calories, low protein for people with kidney issues, such as Suplena from Abbott Labs. Thank you for your question.