They replaced virtually my entire digestive system, most of which was destroyed beyond healing by the radiation. They extracted the stem cells they needed and grew me new, perfectly compatible organs. Exact copies, in fact, of the ones I was born with, but grown to adult size. The whole thing took about a month, with another couple days to recover from the implant surgery.
Then the fun started. Digestive system regeneration requires what was gently described to me as an "adjustment period," as my brand new guts settled into my old body. There was no rejection as there is with foreign transplants like the one my sister had - these organs were mine, with the exact genetic makeup of the originals.
But they were completely new adult organs, lacking the bacteria and other bits of stuff needed for them to work properly. My system was infused with several batches of new intestinal flora, and my stomach chemistry was adjusted several times. Does any of that sound like fun? It's not.
Once I got through the gut-wrenching sickness and started to feel at least a little human, it was time for me to grow new legs. I know it sounds counter-intuitive that growing a new leg hurts more than, say, new lungs but it's true. They can regenerate organs in the lab and transplant them, while a new leg has to grow on your body. And it hurts like a motherfucker.
You would think that attaching a new arm or leg would be relatively easy, especially since they've been able to re-attach severed limbs for a couple centuries now. But unlike organs, the process for transplanting new limbs has never been very successful. Something to do with developing the leg itself to match the stump. So instead of being cultivated in some glorified incubator, my legs would be grown in place, right on my body, which sounded simple but was in fact significantly more complicated.
One problem was that most anesthetics and pain relief drugs interfered with the growth and development of new nerves. I'd been heavily medicated with pain-killers since I got to the hospital, but that all stopped when they strapped me into the regeneration machine. I got to feel every bit of it, pure and undiluted. Mostly undiluted, to be completely accurate - they did try to mitigate the agony a bit.
They administered pain-control hypnosis and something they called "compensatory neural stimulation," but trust me, none of it did much…sort of like giving you two aspirin before setting you on fire. It hurt like hell 24/7 for the entire six weeks it took for my legs to grow.
Doctor Sarah checked on me every day, spending a few minutes examining the development of the legs, but mostly trying to distract me from the pain, I think. It was a noble effort, and if anyone could have managed it, it would have been her. But this shit really hurt. I was irritable and miserable, and I even yelled at my beautiful doctor a few times, which only made me feel worse afterward.
Florence also spoke to me in soothing tones, and she (it?) got the worst of my frustration. Actually, I found the medical AI to be quite an amazing device. A sophisticated computer system that managed my condition and drug intake 24/7, it was also programmed to help alleviate boredom and provide customized companionship to mending patients. Among other things, she beat me at chess about 30 times. She could also do things like turn what was most likely a database of past patient comments into a casual conversation. Something like, "I hear the pasta with mushroom sauce on tonight's menu is particularly good. Shall I order it for you?"
By the way…food. It was about halfway through my leg growth that they actually started giving me real food. Not that I wasn't a connoisseur of various flavors of intravenous nutritional replacement formula - I think that's what they called it - but by the time they actually fed me something solid I almost burst into song.
Solid is a bit of an overstatement - the first thing they brought me looked like soupy oatmeal that had been through a food processor, but I could have waxed poetic about it for hours. Any food that entered my body through my mouth and not directly into my bloodstream was A OK with me.
I was strapped into a machine with my torso disappearing into a shiny metal cylinder that extended to just under my sternum. Below the cylinder each stump extended into its own clear plastic tube that would hold and support the new leg as it grew. Inside the cylinder, in addition to the machinery that powered the regeneration, was an assortment of plumbing that attended to by bodily functions while I was strapped in, immobile for weeks.
I was most concerned with - in order - pain, boredom, and going a little crazy because I could hardly move, but I have to admit it was a learning experience watching my legs grow. At first it was just the bone, growing down from the existing stump at a rate of about 6 centimeters a day. I used to stare at it to see if I could perceive it actually growing. I thought maybe I could a couple times, but I was never sure.
The whole process was monitored and controlled by the medical computer. I was growing legs from my own genetic material, but I needed adult legs, not the baby legs I was born with that grew over 15 or 20 years. Organs were regenerated in almost the exact way they initially formed and grown to adult size, albeit at a greatly accelerated rate. A new liver, for example, would start as a tiny one that would grow, much as it does in a fetus and later a child as it ages.
But my new legs were grafting right onto my adult body. The doctors couldn't grow tiny fetus legs and allow them to gradually increase in size. The genetic material had to be stimulated to grow in a certain way directly on my body, and this was manipulated by medical lasers, electrical pulses, and a variety of other tools.
Once my new tibias and fibulas were finished with their development, I was amazed at the spectacle of my new skeletal feet growing. About the same time my upper legs began to grow muscles, cartilage, nerves, arteries, and the rest of the slimy stuff inside all of us. For a while I was a live anatomy lesson - upper leg showing the muscular system and lower leg the skeletal.
I mentioned that all of this hurt, didn't I? I'd describe what new nerves feel like when they are growing, but honestly, I just don't know how to put it into words. It hurts. A lot.
Doctor Sarah would visit me as often as we could, and we'd talk about different things. Of course, I had realized early on that Doctor Sarah was also Captain Sarah, and that she was every bit as much a marine as I was, and outranked me to boot.
It also meant that, as angelic and patrician as she looked, she probably had not had the easiest life before the Corps. Most of us were plucked from one gutter or another. But I didn't ask, and she didn't ask me either. Since the majority of us had shitty backgrounds, it was traditional to keep it off limits. We were all reborn into the Corps, our old sins expunged.
We were both from New York, and had both lived in the MPZ when we were young, but that's as far into that subject as we got. She received her medical training in the Corps, and before that she made a few assaults, though not as many as I had. She asked me about Achilles, about what it had been like on the ground. She'd served on one of the support ships as surgeon, but never made it to the surface. With a little help from Florence, she got me through the boredom and pain and frustration. I think helping me helped her a little too. The war had not been going well, and I can only imagine how neck deep in blood and partial soldiers she'd been every day.
Once the skin had completed its growth my regeneration was declared complete. That doesn't mean I was as good as new though. In theory, my new limbs were exact copies of my old ones, though the reality was a bit more complicated. I hadn't spent a couple years learning to walk with my new legs, and the neural pathways required to move them were slightly different. It took a month of hard physical therapy before I could walk around normally, and longer before I felt really comfortable with my balance. You'd be amazed at the sweat you can work up holding onto parallel bars and willing your new legs to move a few inches.