This is a gastrointestinal issue post cholecystectomy and has nothing to do with your previous tummy tuck. You need to continue follow-up with your general surgeon and gastroenterologist for your discomfort.
I had a tummy tuck in December, 06 and I started feeling pain in my upper abs about 6 months after that. I associated these pains with my tuck. The pain continued off and on for the next year and a half. I found out I had two stones in my gallbladder about a month ago, (early October, 08) ,so I had my gallbladder removed. It has only been a month, but after I eat almost anything I get the same pains in my stomach that I had before my gallbladder was removed. I had an ultrasound a week ago but they could not find anything. I am a busy mother of two and maybe I try to do too much. Is this too early to worry about so soon?
The issues here are your general medical condition and healing capabilities. Secondly, the location of the scars for your gallbladder and splenectomy, which may compromise the ability to perform a full abdominoplasty. These issue need to be addressed by both your nephrologist and a plastic surgeon.