nutritional problems after total colectomy

I had a total colectomy and then 6mos later had half of my small bowel removed due to obstruction after battling crohn's disease and ulcerative colitis for many years.  I am now having problems with keeping weight on and vitamin deficiencies.  Unable to take supplements by mouth due to no intestinal absorption(or very little)  they give me increased diarrhea and stomach pain and nausea.  Cant seem to find a doctor to help.  unable to tolerate milk/dairy products. also have a thyroid problem  hypothyroidism.  currently on synthroid and cytomel.  what kind of doctor do I see for these absorption issues.  I am extremely fatigued   Low vitamin d , calcium , b12  electrolytes.  Any suggestions?