I'm not sure what the curriculum is for information systems. If you could point me to the course list I might be able to get a better idea.
With that said, I did computer science in university. I actually entered university as a mechanical engineer thinking that that was what I wanted. However, I never took a single mechanical engineering course. It was the best decision of my life. Not only do I love what I do, but I get paid for doing it. My advice to you is to look at the curriculum and decide which courses you like most and go for the major that requires more of those courses. If you follow your passion, success will chase you instead of the other way around.
Realistically, it is important to remember that everything in the world is just a game of economics. Supply and demand dictate who will get a job, who will get paid more, etc. At least in the United States, where I live, the number of students who pursue a math heavy course are far fewer than the number of students who pursue non-math heavy courses. This is the underlying reason why engineers are in such demand and are so well paid. The demand for good engineers is far more than the supply of good engineers.
Here's a sampling of IS courses: