Martman,
Welcome to the forum.
Sorry about your recent UP diagnosis.
Even though my GI told me diet does not affect UC, IMO and experience, it does make a big difference.
I also think I'm slightly lactose intolerant. I can have milk, but beyond a certain point it'll cause me stomach problems.
I've never heard of that before; you're either lactose intolerant or not, so to me it's strange that you can handle milk but not other milk products, especially as milk is the hardest product on the stomach for those who are lactose intolerant.
I drink coke regularly. I also eat a lot of processed foods I think.
Coke contains High Fructose Corn Syrup (HFCS) which many of us UCers have problems with. I know you can purchase Coke which is made in Mexico and does NOT contain HFCS.
Processed foods generally contain alot of salt and nitrates. Also not good for you.
I guess if you're suffering enough with your symptoms that might prompt you to try some dietary changes and you'll see if it makes any changes in how you feel.
I can tell you that many of us, me included, do much better on SCD - specific carbohydrate diet (you can google it), but it's a tough diet, so perhaps in your case you could try: going dairy free, wheat free, and gluten free and see how that affects you. Also, start a food journal and then you can really start to connect the dots.
Also, you didn't mention which drugs you are on?
Are you on any rectal meds - that would be very helpful to you?