I'm sure you're going to get many responses saying exactly what I'm about
You need to get her to a Hospital or GI clinic immediately. She could have any of several complications from this disease. Some of which could be deadly if not treated.
I can only speculate, but it could be a blockage, which you can't ignore.
If you're small town setting can't provide adequate care, then you need to drive to the nearest big city. Get on the phone and start by calling you're family doctor. Get her in tho see him, and get referral.
You're really going to have to take charge with your Mom, and just tell her straight out how it's going to be. You must be firm with the Doctors as well.
Good Luck, it's a tough spot to be in for sure.