Food poisoning and travel insurance

I am writing a feature about consumer rights if you get food poisoning on holiday. I need insurance companies/money experts/travel experts/solicitors to comment on the following:
Does travel insurance cover food poisoning? If so, does is just cover medical costs or repay you for the affected days of your holiday (i.e. if you are unable to leave the hotel room)? Will it cover you if you are not well enough to travel home as planned?
What is the situation if you get food poisoning on a package holiday or all-inclusive - is the tour operator liable?
Can you use a no win no fee lawyer to make a claim against a hotel/tour operator if you get food poisoning on holiday? How does this process work?