What are the best exercises I can do, besides walking, to get back to fitness following abdominal hysterectomy?

Unfortunately, aside from walking there is little to nothing you can do in terms of fitness at this point. I, personally, haven't had an abdominal hysterectomy but a friend who was my martial arts teacher had one and she wasn't even allowed to practice small kicks. Walking is about all you can do and slowly slowly you bring yourself back to a more challenging routine. It was about a year before she began giving lessons again.