Crohn's isn't something you think you have, it usually hits hard. Also, Irridology only spots tissue weakness, I suspect if they were that specific they don't know what they are doing.
Crohn's usually starts out with you rectum tearing open constantly, then progressing to weight loss, vomiting, diarrhea mixed with constipation, anemia and no appetite.
Crohn's from my experience about 95% of it today is caused by Mycoplasma. Its curable, but the treatment times can be up to a few years. Diet helps control symptoms, but the infection will still progress.
When I was sick I went in for dark field microscopy and you could actually see the Mycoplasma infesting my red blood cells. It doesn't have a cell wall, and lives inside your cells provoking the 'auto-immune' response.
I used the Beck protocol, got better, and had another look at my blood. Clear of Mycoplasma.