Which disease is it if segment of proximal jejunal thick without obvious intussesception with no proximal bowel obstruction is it cure in 17year adult?

Probably benign: In the absence of any symptoms, other than gas, this is probably not serious. Segmental thickening of the small bowel is of uncertain significance. Some diseases such as Crohn's or infectious gastroenteritis, may have thickening, but these are usually associated with more clinical findings. If you are having diarrhea, bloody stool, moderate pain, weight loss, then see a gastroenterologist.