Well, even though it is mild, he diverticulitis can definately be the culprit, as it is usually a left side issue, However, the area you describe can also be tied to what is commonly referred to as Splenic Fixture Syndrome. This area is troubling for alot of people, mostly IBS sufferers, but really anyone, as there is a bend there in the colon and air/gas can get trapped there and cause pain there, which also wraps around to the back. I get this every now and then, and can literally feel the bubbles if I push hard enough(Although too much poking and proding is never good!!!)
Anyway, google that and see if it sounds familiar to the issues your having. Since you just had a colonoscopy, I cant imagine the issue being anything other than changing symptoms of diverticulitis, or the Splenic Fixture Syndrome. Hope this helps
Well, sometime I feel some pain there and it really get so worse and I find it very difficult to overcome this as, It sometime happens during the night sleep.I will consult with the doc on this issue.