Short stature can result from endocrinological causes. In fact it is one of the major causes of short stature. The doctor sent your son to endocrinologist
to rule out the hormonal
causes of short stature.
Abnormal CBC results can very well result from nutritional or hormonal causes. But it would be more helpful if you could post the values.
Also you didn't mention about the bone age X ray
result your doctor took that too would help to reach a diagnosis.
I would advise my patients to get a growth hormone
estimation as the next step.
Thank you for consulting HCM, hope to hear from you about your son's progress.