I had the RNY first and I would run like hell from that surgery due to complications/problems and regain. Also, the RNY vit/min supplementation is not all that different from the DS as the years go by. It really stinks to have had bariatric surgery and need to take mega supplements, be fat, have ulcers, limited food choices due to stomach pain, and still try to be on a diet to avoid gaining any more weight (losing weight had become a lost cause).
This was my analysis when I was deciding: Devices are out - no foreign objects implanted, please. Many of us here have already had the VSG or RNY and those do not work. Go the revision forums here and on other obesity-bariatric forums and you will see how many people are seeking revision due to regain or other problems. That pretty much leaves the SIPS (experimental, may not be covered by insurance, risk of bile reflux, fat malabsorption goes away over time), the DS, or going on a diet/lifestyle changes and ultimately accepting your size/health problems.
I'm going to turn the question back on you. What are your concerns? Were you ever able to confirm/refute if DS is problematic for those with IBS? In reading your introduction, you had the lap band removed. You are going into revision territory. How many bariatric surgeries do you want in your lifetime? Some people do have 3+ bariatric surgeries until they find what works but scar tissue develops and it gets more and more difficult over time to keep reconfiguring your insides.
Sorry this is so long... make a list of the information you still need. Then, make a list of the pro's and con's to various surgeries and not having another bariatric surgery.