My stool hasn't been a normal brown color for awhile. it's usually a very light brown to more yellowish color. what causes this? should i be worried?

Brown stool: Brown stool is more the norm. Tan or yellowish colored stools often are due to more rapid transit through the intestinal tract, as often seen in irritable bowel syndrome, but can be caused by liver,gall bladder or pancreatic disorders. Should you have further concerns, consult a gastroenterologist for evaluation and advice.

Yellow stool: There are many reasons stool may change color; some are more serious than others. Light or yellow stool could indicate liver or gallbladder problems. It is definitely a symptom that shouldn't be ignored. Go see an internal medicine doctor or gastroenterologist.