Hi, I have to say your post-op instructions sound very similar to my husband's. Fortunately, he didn't have the kind of experience you had, and was indeed able to walk (walked out of the hospital three days after the op, which had landed him in ICU) - BUT, he hadn't just had previous surgery!
As for painkillers, he was basically on the maximum paracetomol dose (which I think is 2 x 500 mg four times a day), and that seemed to be enough to damp things down sufficiently. But I can't see why someone couldn't be on more powerful stuff, and it must certainly be worth your while asking? Constant pain is not going to help you heal.
My husband was also told that, although he was 'fit for work' ie, deskwork at home mostly, thanks to an excellent employer for which he was very grateful, the surgeon warned him that 'an hour at your desk and you'll feel exhausted like you've put in a full day' so do bear that in mind. Stress, too, is hardly a good idea - would some kind of tranquillisers help? I'm personally a great believer in using them as 'temporary bridges', though I know that men typically don't like to take them (or, indeed painkillers!) :)
Finally, I just wanted to say that, since you don't mention any mets (tumours in distant organs), does that mean they caught the primary cancer on the kidney before it had 'gone out to play'? I do, do hope so, and if so, then I think there are good good (indeed, fantastic!) grounds for being incredibly grateful to that ruptured appendix! A quick browse on the boards here (are you checking 'kidney cancer' too, here - for some reason this type of cancer splits across both boards, with a lot of overlap and cross posting) will show that late DX is all, all too common, because there are so few, if any, discernible symptoms at earlier stages - or, indeed, even at last stages! Around 30-40% of all RCC DX is, so I think I read, classed as 'incidental DX' - meaning the cancer was found when the docs were treating/investigating something else completly, such as your appendix. Someone here went to the doc with a 'tennis shoulder' that turned out to be a bone met, someone else had a bad ankle (bone met), and my own husband just had a persistant cough (lung mets) and had not realised his night sweats were cancer (and didn't tell his GP). Oh, and he had a visual migraine in one eye, as well - jagged lines every now and then. It was a brain met.
However, EVEN IF, the docs have told you it's pre-metastatic the cancer, and that 'they've got it all' PLEASE insist on a full torso CT scan (and, indeally, a brain scan as well, especially if you have ANY possible symptoms, such as visual disturbances, trembling/numbness in the limbs, or new headaches, or pressure behind the eyes, or any mental confusion). Some docs are very pro-active and concerned, some are not. Some surgeons like to tell you that 'they've got it all out' and be overconfident about your conditoin. ONLY A CT SCAN will show if you have any mets anywhere else, eg lungs. You MUST insist on one, whatever the docs say. It's your life and, bottom line, in the end, only you and those who love you care about you - your doctor may not. (And your employer certainly won't! So NEVER make your job take precedence over your health and life!)
There is a theory now that cancer starts to metastasise much earlier than originally thought, with 'micro-mets' lurking in the blood stream, etc, ready to 'nest' in nice warm, unwary organs!
Also, as you know, RCC is a come-back king, and there are people DX and treated at pre-met stage, who still go on to develop - sometimes years and years later - metastatic cancer, either in places like the lungs, or in the remaining kidney, or in the renal bed of the removed one. So, for the rest of your life, you MUST remain on 'cancer alert' and have at least one CT scan per year. The good thing is that this will catch any recurrance earlier than symptoms showing, and it will also spot any OTHER type of cancer in the torso as well (some exceptions, eg bowel, testicular, etc)
All the very, very best to you - if they HAVE caught this pre-metastatic, you are a very, very lucky guy. (And even if they haven't, or it arrives later, this is, after all, the best time ever to have RCC, with the new drugs and therapies around.)
Best, Julie.