My 15 month baby boy sonography report.

My son was suffering from urine infection last month.But now all urine report came normal and he is also not showing any symptoms but as per doctor done sonography and it's showin g and it's showing mild dialation 2cc and left lower uterer not visible.Doctor told us it's Normal and suggested sonography again after 3 months.As my baby suffering from constipation and due to that he might faced urine infection and cause swelling.So no doctor given him 1 month constipation medicine.So any expert who help me to understand his report? What it actually saying? If constipation cures then is that swelling also cures? Please need guidance as we are very worried.Currently he is absolutely fine and no symptoms.i have attached report for reference