Irriatable bowel syndrome symptoms? and anxiety?

i dont get it and is bothersome i get symptoms like change in bowels. constipation and straining of bowels. pain in groin and abdomen at times. feeling of urgency to urinate and no pain when urinating or releasing bowel but the feeling of my bowels or bladder isnt always empty? i do have anxiety disorder and doesnt help the fact cause me more worries i constantly think i have bladder or colon cancer. im 28 male and these symptoms only happen when im sitting in chair or laying in bed and im relaxed. i do sit in chair with bad posture as well just trying to pinpoint what to do doctor said everything was ok he did blood test and urine test 2 months ago.