Frequent loose stools and nausea

Have been having frequent loose stools(not always diarrhea) on and off for about 1 year. In last few months have also developed daily nausea, ache at bottom of esophagus and some on and off pain in my right hip and shin. Had ultrasound and pap to look at female parts and all is fine there. Decided to go for Colonoscopy this week to hopefully rule anything out. I have not lost any weight and don't feel I have a decreased appetite. Have been very stressed over the last few years so hopefully it's just IBS and not anything bad. If nothing is found then maybe I should ask for an upper gi to look at my stomach. Could this be an ulcer? Any thoughts? I started to get more concerned when the hip and shin came into play. I hope it's not bone or stomah cancer. Yes, I'm a worrier!