Why has my friend been throwing up for months?

[Amberdmeyer]

He has lost eighty pounds and is on the brink of being put on a feeding tube.  The doctors can't figure out what is wrong with him.  They have tested for and eliminated the following:

Crohn's disease
H. Pylori
Chagus
A blockage in the celiac artery
Tick born illness
heavy metal poisoning
pancreas
Gastric emptying issues
brain abnormalities
Food allergies
chemical and metal contamination
UC

He has had all of the following tests ran:

Special blood test to check for known parasites
A Special CT
Brain MRI
Camera pill
3 colonoscopies
small bowel and esophagus have been scoped
biopsies throughout his entire digestive system
all internal organs have been pinpointed with multiple CT's
blood flow to all organs in the digestive system

He is currently scheduled for a cortisol test.  He seems to be losing hope.  Day to day functioning has become very difficult and he is worried about keeping his job.  Any advice you can offer is greatly appreciated.