I've Had Severe Stomach Pain With Rectal Bleeding On And

I've had severe stomach pain with rectal bleeding on and off for 3 years. I have had 2 colonoscopy with one removed 3 polyps one cancerous. Two endoscopic test one with a pill. I have no ulcers or hemroids. Been to the ER 4 times this week with no answers. I'm not making this up I need to know what's going on. It's frustrating living like this day in and day out with drs thinking I'm out for meds. I could care less for the meds I want to know what's wrong with me it's literally killing me.