This may be a bit petty, but it's been grinding my gears for a while. Kids - The acronym "IBD" stands for "Investment Banking Division". As in - the division of a bank that performs investment banking activities. This includes things like M&A, capital raising, restructuring, etc. You can find this definition in the WSO FAQ.
Similarly, the statement "I want a career in IBD" is wrong and makes you sound like a retard - say it out loud. The phrase you are searching for is "investment banking". As in - "I want a career in investment banking (IB)". Get your terminology right, because when you write sentences like "What makes IBD (read - investment banking division) a 100hr/week job?" you sound like a high school kid throwing out acronyms to sound cool.