What is the treatment for barrett's esophagus that is best and has fewest side effects?

Barrett's risk & tx. Barrett's epithelium replaces the part of your esophagus that is damaged by reflux. Yearly risk of barrett's tissue turning into cancer is low, but roughly 65x likelier than in patients without barrett's. Prevention & early detection is key, & treatment of gerd is important in patients predisposed by longstanding reflux. Dysplasia in barrett's needs close follow-up, can be endoscopically destroyed.
Consult your doctor. Such an issue is best resolved through a discussion between the patient and her/his doctor. Different people have different values about side effects and effectiveness of treatment.