Thank you for your query on Healthcare Magic,
Your child seems to have constipation
Usually with constipation there will be accumulation of gas leading to flatulence
and swollen stomach.
Give plenty of oral fluids and water.
Give mashed vegetables, fruits as they contain dietary fiber
and it will make stool soft and easy for defecation.
You can give lactulose as prescribed by your doctor during constipation.
I advise you to go for throid testing after consulting your Pediatrician
as it will present with bloating stomach and constipation.
Hope I have answered your query.