Hi,
Sorry to hear about your mother's complication. I know that major surgery takes a huge toll on the body, the anesthesia can make somebody feel horrible for months. I only had a mastectomy and felt horrible for at least a month post-op and fatigue became my middle name. But after a month more treatments came in the picture which added to fatigue, long term. Your mother hasn't had chemo or radiation. Still, surgery is enough to flatten a person for many weeks.
I would be pretty confident that the experts at Mayo would be aware if there were complications of any kind-at least I hope so! CT scans are done at the 3 month follow up barring unforseen complications such as blockage or bleeding.
It's common to lose weight after a cystectomy, even 40 or 50 lbs is not unheard of. Is she on pain meds? This would cause sleepiness and lethargy and contribute to constipation and no appetite. Exercise (walking) is very important post-op.
Try to find out if there's a social worker you could speak with connected to the hospital, who could discuss what's the best way to introduce the topic of antidepressants, or guide you to who would be the best doctor to ask about this. Or ask the physician in charge. See if you can get a call through, or make another appt.
I hope things change, with spring approaching. You mother may be experiencing a post-traumatic shock after such a life altering experience, the seriousness of the diagnosis and the reality of life post-op. I'd say try to encourage her to talk; to you, your father, her family and friends. Maybe she needs someone to vent to and doesn't want to burden her loved ones. Perhaps she's unable to express her fears and doubts and needs an outlet for that, and maybe a third party would be of help.
Take care,
Wendy