Tummy Tuck or Liposuction After Colon Resectioning

I doubt that you need a second tummy tuck after colon surgery.  With weight gain and having a previous procedure, it's unlikely you would need more fascia tightening and skin removal.  Nevertheless, I would follow the advice of a competent plastic surgeon.

I agree with the other surgeons that achieving your optimum state of health is important before surgery, but would like to add that whether another tummy tuck (in some form- there are many techniques and I actually perform 4 variations of the tummy tuck) or liposuction is best for you when you do have surgery will largely depend on what you look like now (do you have loose skin, or just excess subcutaneous fat, and are your muscles loose), what you would like to achieve, and whether you find the surgery, its recovery, and risk profile acceptable.
Your best course of action would be to commit yourself to a healthy lifestyle that you think you can sustain over the long term, allow the benefits of that healthier lifestyle to take hold (your weight ought to be stable for 4-6 months before surgery), and then seek the opinion of a Board Certified Plastic Surgeon in your community. This would give you the best chances of ending up happy and safe.