Gissy, have you done any modifications to your diet to manage these issues?
Motility problems are annoying and can make you miserable. I suffer from a similar situation as you - except I have a diagnosed bowel disease and my GI just shrugs the motility issues off. I don't have such bad flatus anymore because I'm treating my bowel disease, and I've stopped eating foods with lactose, and I've stopped eating legumes except when I prepare them myself. I also recently went gluten-free, and that has taken care of the rest of the gas issues I've had for the past 10 years.
I'd suggest you talk to your doc about
the motility problem. Mine suggested a daily dose of miralax. Another DR suggested senna, which she prescribes to her spinal cord injury patients to help with their motility. I've adopted the senna idea, and have started really slowly by adding one tablet to my pill box every other night (the recommended dose is 2 tablets per day). I think it's helping me.
Please go see your DR and rule out any disease in your bowel. Type I diabetes is an autoimmune condition, I think, and if you have one you are more likely than the average person to have another (like Crohn's or UC or asthma, right?). Sorry you're suffering so.
Oh and the weight issue speaks to a bowel disorder too. So please go talk to your DR.