Definely the right side for me...not even for a minute on the left, my pouch 'flops' over and it is hard to "unflop". As for tubes/cahteters etc, depending on you and your experience you can cut extra holes in certain catheters (parctice on old ones) by pinching the spot flat where you want the extra hole, take a sharp knife (ooops...be very careful to do this slowly, over a counter top and do not cut yourself!)...you just cut up a semi-circle through the pinched area and you have an extra hole...you then need to file it, melt it in hot water or burn it and smooth out the edges so they don't cut you. It does help for some of us but it then makes the tube a bit more bendy and flexible. Harder to push in.
I have often walked into surgical supply stores 'window shopping' and picked out different tube to try and the docs and nurses here are very nice about that sort of thing and let me pick out and try anything...if (and this is for you Vanessa) you cannot get the tube in and the silcon one is too flexible to go round the bends then reinforce it through the inside with a stiffer wire...it gives it 'support'...when the tube goes in, pull the wire out and you are fine.