What dose having bright yellow/ mustered coloured stools sergest or signify?

"What goes in must..: Since the color you described does not "ring a bell" as signifying any particular disease entity it is likely that your diet may contain clues about the color of your feces. For example certain food coloring dyes will persist through the journey from your mouth to your bowel movements (EG: Orange dyes) Hope this helps! Dr Z

Poop Colors: The color of stool is not usually concerning, as it reflects a lot of things we eat. Dark black, red or white stools are the only colors that are worrisome.

Faster stool transit: Stool color is dependent on bile. Green bile gets excreted from the liver into the stool. As it travels through the bowel, the bile is acted on by gut bacteria and gradually changes color from green to yellow to brown. If the stool moves faster through the gut, bacteria have less time to change the bile color. This is not a problem unless having persistent diarrhea.