If there is one cancer that i would not like to get, it would be bladder cancer, not because the prognosis is that bad, but that the treatment is almost as debilitating as the disease itself.
Your friend has had a total cystectomy for malignant disease which although major surgery is not that uncommon. The problem is, what to do with both ureters ( drainage tube between kidney and bladder, which are now left "dangling")
They can be brought to the surface of the skin (urostomy) or, more recently artificial bladders are made from a piece of intestine and the bladders are joined to the piece of intestine.
From my description, one glaring problem stands out and that is at some time the urinary system becomes in close contact with bowel contents and that is bad news, as urinary infection is inevitable and that is happening to your friend.
\\\and I may be way off here but is is possible that there is a perforation in the bladder which is causing waste to get in from the bowel\\\
She has no bladder.........but if you mean could the artificial bladder be leaking, then that is very unlikely as it would cause severe peritonitis and that would be obvious to all.
This is just a resume of my knowledge as i am not an expert in this field and up until now have no personal experience of this.
Rough call for your friend and not a good outlook.