Would kidney or intestinal ulcers cause pain?

I've been having pain in my waist (kidneys area) front and back, and when I urinate sometimes it feels irritated, not necessarily burning feeling, more like an itch. Also I experience tingling and sometimes pain in my . I went to a free clinic and the urinalysis looked fine, I got an STD test just in case but the results are not back yet (I haven't had a partner in months so I'm not terribly sure STDs are anything to do with it, more my poor dietary choices). I'm convinced these are ulcers, especially since stress seems to aggravate the pains, but I'm wondering if that explains the pain too.