You can solve the post-mealtime accident problem by being prepared to have Rudy go out the second he is finished eating. If you take him out on his leash, have his harness on him before he eats so that you can hook up the leash and go straight out the door. Most potty training methods recommend taking the dog out immediately after meals.
Relative to the other accidents and waking up too early, has your schedule or routine changed? Keeping a consistent bedtime and waking time will help him to stick to a schedule. Wear him out playing and/or trick training, anything stimulating, before bedtime. Make sure he has a potty break immediately before going to bed. All of these things should help eliminate accidents or waking too early.
For surgery, did you have the pre-op blood tests done? Be sure to follow the doctor's post-op instructions about limiting exercise and no bathing. You may need a cone to prevent Rudy from licking the surgical site. Sending best wishes for your boy for a speedy recovery.
