you can come back under business visa in no time after you went out of doha.....actually this happened to my Engineer friend and I took a business visa for him and now he is back...and he needed the NOC for his transfer for a new work visa...

but there is a new law with this kind last month....because if you dont have an NOC when you request for a new business visa your visa will not be approved...it will appear NO DATA FOR THIS ENTRY....I think this law started last month.....I will check with my friend what are the new requirement for you to re-enter Doha and get back to you...

hope this helped you....if you need help just send me a msg...

Gudluck...