hello any sudden change in bowel movement requires investigation. i would advise yo go to er and get evaluated..when i get constipated i too feel sick but you need to get this checked out.
im not sure if the hernia is related to this but there is obviously a problem..why wait when you can be seen too today.
you don,t mention how old your baby is and not unusual to be constipated as you are sore after the birth..but you mention things got wierd couple of months ago so i would say there is possibly an underlying problem..
let us know how get on.