SCP Foundation

The main danger of ruptured intestines (besides the trauma that ruptured them in the first place), would be septic shock from your bowel culture getting to the rest of your body. Not all of these bacteria species would eat your body, but some will, and that's definitely enough to kill you. Not to mention that once you're dead, your skin stops regenerating, so outside bacteria can get through and quicken the job. As for the gut flora dying with you, that's not likely unless they starve, which most will not until your body is gone and they're just stuck in a containment cell with no food.

EDIT: Also, there are lots of the same species of bacteria that do a ton of different things, hence the term "strains" being tossed around so much. E. coli, for example. Some strains secrete toxins that make us sick. Some don't. Regardless, both can be found in our large intestine, and are a major reason why fecal contamination is dangerous.