colon side pain

colon side pain
I have had this pain in the upper left of my stomach on the lower left rib?

I have had this pain for about 3-4 years, but even more last year. Sometimes the pain in the back and scapula. I had an x-ray done and the doc told me is constipation and wind trapped and gave me laxatives. Constipation is cured but the pain is still there. I'm really scared as I am thinking intestine / colon and liver cancer! afraid to go to the doctor for more tests!