Toilets, Sinks, Showers, Tubs and Disposals - toilet drain in 6 in joists

I'm getting different stories about the ability to put a toilet on my 2nd floor room which has 6 inch floor joists. I have some people that say the bend radius can not be done. I do not have to cross any joists, just parallel to the joists for approx 6 feet then down to the closet below. Any suggestions?

Your joists are only 5 1/2", so if you take a 4" pipe, you only have 1 1/2" to turn the radius in to keep it within the confines of the joisting. The total space taken up by the bend alone is something around 7", so I am not sure you will be able to accomplish this, considering you have to allow 1/4" per foot drop in your line to the place where it goes into the main drain. But to satisfy your curiosity, visit a plumbing store or big box and try the fit and measure the components when slipped together.

This is easily accomplished using 3 inch pipe and is "code friendly". I just added a bathroom to a second floor that had the same situation.