I am 33 year old after I gave birth to my son I get lower back pain it runs to the side of my back and sometimes I feel it in the front of my stomach. I am not losing weight, I have a good appetite. I have hypothyriod since I was 27 years old. I drink Advil and it goes away but sometimes it comes back. I am just scared it might be something serious. Do you recommend I go and get my liver and kidneys checked. I have already went to the doctor and they took blood work but they didnt find anything. It isn't all the time. It comes and goes. What should I worry about also my stool is light brown, sometime dark something light. But always brown. I have been under a lot of stress and I am a worry wart just wanted to make sure I was ok. Also I was told I have an umbilical hernia, not sure if that is why I feel stomach pain. What do you recommend I do should I get specific tests done???