I think it's quite probable that your daughter's symptoms are neurologically based, but I don't know enough about MG to say if that's the cause or not.

I've had those exact same ones myself and my Neuro has confirmed that mine were brought on the chronic neurological condition that I have .....not that I'm suggesting she has the same disease as I do by any means, just that the cause could be similar in origin.

Neurological symtoms can come from the brain or the spinal cord in the back.

I daresay her back has already been considered as a source for her bladder and bowel disturbances, because there are conditions of the lower spine which can cause the symptoms you describe..... growths, slipped discs, spinal stenosis to name just a few.

You'll find charts on the Internet that show which spinal nerves control which functions. For example... the last of the Thoracic Vertebrae (T10) along with some of the Lumbar Vertebrae, control the large bowel and the urinary bladder, while disturbance of the Sacral nerves can also have some detrimental effect in the same area.
Here's the link to one such chart : http://mississaugachiro.com/interact...erve_chart.php

Also, have a read about Gastroparesis. There are many causes for this condition, one being disturbance of the Vagus nerve (neurological again), and although it wouldn't explain her urinary incontinence, it certainly would explain the bowel symptoms.

It sounds like the doctor was talking about a total colectomy when he mentioned the bag. That involves removal of all the large bowel which is rather a drastic step to take for an 18 year old, and not one to be rushed into. I daresay if her symptoms go on for many years, or lead to bowel obstructions because the waste isn't moving through the bowel, then that's something to be considered at a later date, but not until all other avenues have been exhausted. I had a partial colectomy 3 years ago to remove a growth and I was lucky enough not to need a bag. Should I need surgery in the same area again, I doubt I'll get out of it so lightly.

Good luck to you both. I hope you find some answers soon.