Can any gas other than nitrogen cause decompression sickness (the bends)?
Yes, it is possible to get decompression sickness with other gasses, such as the &quot;oxygen bends&quot; or oxygen decompression.  For instance, in this study, they demonstrated that oxygen decompression sickness in mice.  Another study demonstrates a more common non-nitrogen decompression sickness - helium bends.
Undoubtedly you will be wondering at this point why breathing pure oxygen would diminish (or, in certain circumstances, completely remove) the risk of bends as compared with nitrogen.  The reason is simply that oxygen, unlike nitrogen gas, is constantly being metabolized by the body tissues.  Consequently, even if the oxygen levels in your body fluids become elevated, they would have to be way higher than normal levels (like in the first study linked) before you would start to have it accumulating enough to form bubbles.
The body is designed for the shipping and handling of oxygen (think haemoglobin &amp; myoglobin).  Nitrogen, on the other hand, is relatively incidentally present - so long as atmospheric pressure remains relatively constant (which it did until we devised technology allowing us to radically change it), it's present in low levels in all the body tissues without causing any trouble.