Excessive Thirst and Growth Concerns in a 23-Month-Old Child: Potential Causes & Next Steps

Question
Hi ,My daughter has had frequent episodes of diarrhea since 7 weeks old despite this she has been off the growth charts for height and weight.At 18 months of age she started drinking excessive amounts of water up to 4 litres a day. She also has a heart murmur. She was tested for diabetes insipidus 3 times .Vasopressin was never given during these tests. Now i notice her head measurement is over the 100th percentile and it was going along the 25th percentile.Her height and weight are going down they are both going in a straight line on the chart. She gets frequent fevers and has now had a total of 6 convulsions some lasting 20 mins. I wanted to know if it is normal for her head circumference to jump from 25th to 100th given her problem with excessive drinking /urination. I would appreciate any advice you could give me . Thank you  

Answer
Certainly it isn't normal for the head circumference to rise rapidly, out of proportion to the other numbers.  The D.I. complicates issues.  If it were my child, I think an evaluation by a pediatric endocrine/neurologist is in order, especially with the  D.I. and the seizures and the increase in head size.

Hope this helps...