Diagnosis and treatment for bacterial infections

I am going to have an endoscopy procedure followed with a small bowel biopsy.  The doctor wants to see if I have a malabsorption syndrome that is causing me to continue to lose weight.  If this is the case, I am wondering what the process is for diagnosing and treating this condition.  I am also wondering what are the ways that people gain their weight and body tissue back.  Thanks

[boron]

During endoscopy, biopsy of duodenal mucosa will be done and check for celiac and Crohn's disease.

Other possible tests are:
- stool fat test (increased amount of fat is in fat malabsorption).
- A1AT (alfa 1 antitripsin) test is for diagnose of protein losing enteropathy
- pancreatic function tests
- D-xylose test to distuinguish among intestinal and pancreatic causes of malabsorption
- Capsule endoscopy or double baloon enteroscopy show entire small intestinal mucosa

Treatment (diet) depends on the cause, so first you need an exact diagnosis.