Left abdominal pain, diverticulitis??

I have been experiencing lower left abdominal pain for 9 months now; pain almost feels like a stabbing/cramp, can radiate into groin and hip but feels better when laying flat on my back Used to experience diaherea, till I changed my diet but do have periods of constipation I recently had a ct scan that showed thickening of ascending colon which I know is right side but my pain is on the left, currently waiting on a referral for the specialist. Does anyone know if diverticulitis can show up like that on a catscan? Or if this pain I’m experiencing could be that or something totally different.