Everyone's stool starts out yellow or greenish (color comes from the bile).With time the bacteria in the colon turn that yellow or green color to brown. The more color that is changed, the darker brown the stool is.If your stool move faster than the color changes then you will see a yellower stool rather than a browner one.So everyone's stool starts out that yellow color (or sometimes more green than yellow) it is just some people that get to see it. Depends on how many of which bacteria you have and how long the stool is in there.Now different foods also add to the color so if you have 1 BM a day and eat 3 meals and 2 snacks it isn't likely that all 5 meals/snacks are distributed evenly in the 1 stool. So different parts of the stool are from different meals (and had more or less time in there to get color changes) so may not all be the exact same shade.Deep analysis of the stool to where you see every little variation is not likely to tell you anything about your condition. Normal stool is not all the exact same color in all parts and the same color every day, and there is undigested matter visible in normal stools of normal people so much of what IBSers notice only when they first start really studying the stool is stuff that used to happen all the time and they just flushed it too fast to notice before.
