Thank you for your query,
Not passed urine for 2 days and decreased oral intake of fluids and food are alarming symptoms in a 11 months old child.
This is suggestive of decreased activity and signs of dehydration
and the child needs immediate consultation with a Pediatrician
to assess his activity, dehydration and to look for the causes of this symptoms and their treatment.
So consult your doctor as early as possible.
In mean time you can give ORS like Pedialyte
may be due to his decreased oral intake of fluids.
Hope I have answered your query.