Hi there.. you have inflammatory bowel disease- ulcerative colitis which is an autoimmune disease which is due to genetic and environmental factors combined effect..please consult gastroenterologist and treatment includes immunosuppresant agents and along with it you have to do diet control like low residue/low fibre diets, and low FODMAP.. Nutritional deficiencies are present in IBD due to Malabsorption, diarrhea, and GI blood loss. Deficiencies of B vitamins, fat-soluble vitamins, essential fatty acids, and key minerals such as magnesium, zinc, and selenium are extremely common and so multivitamin supplements,foods rich in vitamins and minerals have to be consumed..