You can bill both. The bx would be 43239, and the dilation could be one of several codes depending on the method used. My docs seem to prefer the Maloney Bougie, which is a 43450, which you have to use a 51 modifier for when billed with other EGD codes per CMS guidelines. The other dilation codes are also codeable (43248,43249), as long as you use a 59. Also, be careful because there is another dilation code (43245), but that is for a gastric outlet obstruction, and not esophageal dilation. Hope this is helpful!