Hi, this might sound strange but from the gastro issues and you mentioning nearly passing out. Look up a condition called POTS (Postural Orthostatic Tachycardia Syndrome). The reason I mention this is my daughter's calprotectin levels above 500 so referred for urgent colonoscopy. (People keep mentioning IBD but there is also bowel cancer in the family). Unfortunately she could not tolerate the full procedure but they have taken biopsies, awaiting results. But while all this has been going on pretty much every time she stands up her heart rate elevates causing her to either feel she is going to pass out, or has on a few occasions. Apparently from my research POTS can cause gastro and lots of other issues. Can be linked with MCAS. I don't know what any of this means as awaiting results and to see gastro Dr as well as she has been referred to see a cardiologist. I understand how stressful this all is as I am worried sick as she is ill everyday. I hope you have managed to get some answers and are feeling better and less stressed.