Since there is blood which you can see, it is coming from the lower gut. The possible causes are hemorrhoids, rectal polyps
, colon polyps
, diverticulosis (outpouchings from the bowel wall), inflammatory bowel disease (IBS, Crohn's, Celiac, ulceative colitis), or dysentery. Hence all these causes need to be ruled out. . You will need to consult your gastroenterologist again. Hope this helps. Take care!