esophsgus

my wife is 62 years old. She is having the difficulty while eating. After eating 3-4 bites some kind of foamy white liquid coming back to her mouth. Then she has to go to spit it out and slowly finish her eating. Now she is eating half amount of her normal meal and loosing some weight. She feels uneasy for about 30 minutes or so after eating and then after she is fine. no heartburn at night or anything like that.She had Upper GI endoscopy and shows Findings: (1)  A benign-appearing, intrinsic stenosis measuring 1.5 cm(inner diameter) was found at the gastroesophageal junction ans was traversed.
(2) no endoscopic evidence of: Barret's esophagus in the lower third of the esophsgus.
(3) the soomach was normal.
(4) the examined duodenum was normal.
Impression:  Benign-appearing esophageal stricture.
My question is what do you think about this problem ?  How do you treat ?   What is the risk if you don't treat at this time ?  Howlong she can wait before it gets worst ?  What kind of surgery you think if needed?  It shows 1.5 cm inner diameter  ...what size should be normal?
I hope you will answer to help me.
Thank you.