Any illness effects mental well being. Those studies cited above probably exist for other illnesses as well. When you get a stage 3 cancer diagnosis I can assure you that your mental well being will not be rosy and it will not all look like rainbows and unicorns out there. I don't think there is anything unique or special about those who suffer from IBD as opposed to other chronic or potentially terminal illnesses who are dealing with the same kinds of mental health issues. It seems to me to trivialize the suffering of others to create these kinds of categorical distinctions and associations on one disease only. Anxiety from IBD and anxiety from having cancer isn't any different. In fact having dealt on some level with both illnesses, there was a lot more uncertainty and anxiety with my cancer diagnosis. I designed and executed a complete bucket list before I ever croaked from cancer and I never developed a bucket list before having surgery for IBD, although my colon dissolved in my surgeon's hands when removed. The cancer treatment had a lot more uncertainty.