Live Lizards, For 13 Years In Girl's Stomach, Slowly Poison To Death,

A show called MythBusters on the Discovery Channel actually Busted this myth back in episode Episode 9 where they researched the myth of

Then they'll journey inside the human body, where they'll take on a whopper. A woman claims she swallowed an octopus egg — and then gave birth to an eight-legged offspring

Here is a link to the episode guide MythBusters
Sorry but they do not offer much more info than what I post here.

The thought of something "living-off" of the human body has to be one of the darkest, primitive fears that we could have. Just the thought of some parasite deciding to call your body home, sweet home can make even the strongest squirm.
While it's not uncommon that some species of insects will readily use the human body to lay, incubate, and feed their young this story is pretty much impossible. First off, as far as I know lizards need oxygen to survive and I don't believe that the stomach is an oxygen rich enviornment. Secondly, what were these lizards eating, the chewed up remains of her food or were they eating the lining of her stomach. Finally, these lizards would have been broken down by her stomach acid rather quickly. I don't believe you could take any lizard alive today and throw into a vat of hydrochloric acid and watch it thrive for several years. We have to remeber that the techniques used to diagnose medical illness are a little more improved today as compared to 100 years ago. Modern science has shown that this is absolutely, positively, completely a hoax or an example of some misguided doctor. With that said, I never completely rule anything out so I guess it could be possible