Randy Orton seems to be doing well, despite his reported back issues.
A Randy Orton fan account on Twitter posted some photos of Orton at a swimming pool in Missouri and he seems to be in good spirits. He has also slightly changed his look by shaving his face and mustache. Also, as you can see, he looks to still be in great shape so his back issues don't appear to have affected his workouts.
Orton hasn't appeared on WWE TV since the May 20th episode of WWE Friday Night SmackDown where he and Matt Riddle lost to The Usos. Before the match, Riddle reportedly had to get some work done on his back so he could get through the match and the feeling is that his back is so bad that he may have to get surgery, which would keep him out of action for the rest of the year.
It's unclear when he will undergo surgery but the photos below would indicate that the surgery hasn't happened yet since it's tough to move around after that kind of procedure. It's clear that he is off SummerSlam because the original plan was for Orton to challenge WWE Universal Champion Roman Reigns on that show. Brock Lesnar was brought back to take Orton's place on the card.