Pleural Thickening???

Hi! i had my chest xray and the result says i have pleural thickening. Can any one explai it to me? I'm kinda scared now because this is jusy for my clearance because i will undergo colonoscopy. I did'nt expect this because all I thought that my shortness of breath and chest pains are due to my anxiety problems (health anxiety to be exact).

I thought that pleural thickening was caused by being in contact with asbestos. Why do you need a colonoscopy? 

I will undergo colonoscopy beause of adominal pain with change in bowel movements.

im sure i was not exposed with asbestos.

Hope it all goes well