Red colored urine is not always pathological or disease associated.there are causes like ingestion of various drugs, foods (blackberries, beets), or dyes used in food and candy,may be one of the cause of red colored urine.
In your case,there is one of the following common possibilities.
-glomerulonephritis
-UTI (
urinary tract infection)
-traumatic cause
-meatal stenosis
to rule out causes,you had to
consult nephrologist.
do some basic investigation like
complete blood count,urine microscopy and culture,renal function test,blood urea nitrogen,
ultrasonography abdomen and pelvis.
special attention should be given to blood pressure and check for edema,
abdominal mass,headache and various symptoms.
mean while you should give plenty of fluid to him and start antibiotic according to your consulted doctor.