What Might Be Causing Right Lower Abdominal Pain, And Flank Pain After Eating Fatty Foods When I Have Steatorrhea?

Hi! I have a problem about my stomach but i think my stomach linings is involved but not sure I have steatorrhea symptoms and I have stomach pain at my right lower abdomen but whenever it s press it doesn t hurt and whenever I ate fatty food I experience pain in flank I want to know what s causing this?