Are there in London markets for selling food for Crohn's?

Some things that are safe for many are salmon. Rice. Plain white pasta. Mashed potatoes without onions, garlic, peels. If you talk to the chef I'm sure they will be able to help you out.
Maybe call beforehand and give em a headsup.

I think if you have access to a kitchen, you can find a basic market and buy the stuff you need. If you are having to eat out all the time, then that is much more difficult.

Hi Minnietoty, I don't know of any such thing as a place that sells safe food for crohns. I'm not sure that's possible when you think of all the foods that work for some people but make others ill!
When I eat out in London, I usually have salmon or other fish. I have to ask for vegetables to be very well done or I just don't have them, and you can usually get mashed potatoes. In cafes and cheaper restaurants you can always get a baked potato with butter. There are plenty of health food shops (one chain is called Holland and Barratt) and large supermarkets where you can buy organic fruit or vegetable juices if you feel you're missing out on vitamins.
Also I suggest for the first few days drinking bottled water, as I find when I'm abroad or even in a different part of Britain, it takes me time to adjust to the local water. Maybe that's just me!
I hope you have a great time in London, and there is an enormous variety of food and restaurants here, I'm sure you'll find something.

Penelope -marie, thank you so much. I really appreciate the recommended places and recipes.
Take care :)