Curry is an overused term for anything spicy. Over here it's usually in reference to Indian but in reality, you get curries in lots of asian cuisine - Thai and Japanese spring to mind.
I dont' have the info at my fingertips but if I'm not mistaken, curry only technically refers to a spice mixture - hency the vast array of curries! So yes, you can have extremely mild to extremely spicy curries. Likewise, very dry curries to very wet (saucy) curries.
If you have a sensitive stomach, I'd start with the 'korma' type curries though these can be a bit heavy and filling.
And to the person who is allergic... since 'curry' refers to mixed spices, there's probably only one (or more) that are the culprit. Mustard is a good guess but it could be any number of them. But since you don't even like the smell, probably not worth figuring out what it is unless you're worried a spice might turn up in another type of cuisine (such as cumin or corriander).