My 8y/o son wakes up in the middle of night telling me he cannot sleep because he keeps hearing voices. he also self talks a lot longer and more frequent recently. is this just a normal developmental stage or should i call his pediatrician about it?

Talk to pediatrician: It sounds important enough, causing distress and insomnia.

Call his pediatrician: These could be signs of early schizophrenia

It is atypical. See : his pediatrician for referral to a child psychiatrist & a child psychologist for evaluation & treatment. DO NOT question him; let mental health professionals differentiate obsessions from hallucinations & anxiety from psychosis. Take in a written history of onset, frequency & duration of his symptoms, relation to your Colo-rectal cancer surgery & a 3- generation family mental health history.

Child's sleep distur: Is there a possibility that your child experienced some trauma? Not necessarily abuse, but if the symptoms started in a short period of time, something may have happened. I wouldn't assume anything but if you take your son to a Psychologist expert in treating children, they can do a complete assessment and see if both therapy and possibly medication may help. Recommend no delay, the sooner the bet