If done, plain x-rays of the abdomen may disclose calcifications within pancreatic ducts (evidence of prior inflammation and hence chronic pancreatitis), calcified gallstones, localized ileus of a segment of small intestine in the left upper quadrant or the center of the abdomen (a "sentinel loop"), or the colon cutoff sign (absence of air in left colonic flexure or descending colon) in more severe disease.