Welcome to Just Answer and thanks for your question. H. pylori affects the stomach and is usually eradicated with triple therapy along with several weeks of acid suppression to allow the stomach and lower esophagus to heal. Biopsies during colonoscopy are taken when polyps or anything suspicious is seen during the colonoscopy. Interior samples of the colon may be taken if there are abnormalities seen. It appears that the things seen on your CT scan were not internal to the colon. You cannot take biopsies through the lumen of the bowel to evaluate wall thickness, etc.
Think of the colon as a garden hose. Water going through the hose is internal to the hose. The air surrounding it is external to the hose. If you cut a hole in the hose (take a biopsy) through the hose wall, the hose leaks water into the exterior (your abdomen) setting up the possibility fo peritonitis. Therefore, you can't take a biopsy through the wall of the colon.
What the CT found was that the hose was thicker than the average garden hose. One cause of wall thickening is chronic constipation. Pericolonic stranding is a result of inflammation causing swellling of the adjacent fat around the colon. This is often seen in different types of colitis (inflammation of the colon). Wall thickness doesn't necessarily have anything to do with cancer. It is often seen when there has been obstruction, as in constipation. At this point they have seen no cancer, no IBD, but you do have signs that you've had bowel inflammation. Now they need to find out what has been causing it.