Could bowel impaction, cause pain under the rib cage on the left side?
Yes it could cause pain under the left side of the rib cage. Remember that the splenic flexure of the colon lies in this area. Even though this may not be the site of the impaction, pain may be felt in this region. You should report this to your doctor, as it may be a complication of your condition or even due to other conditions unrelated to your gut.