White stool isn't normal you should let your doctor know. White stool is caused by a lack of bile which is a digestive fluid produced by the liver and stored in the gallbladder there for stool gets its normal brownish color from bile but if your liver doesn't produce bile or if bile is obstructed from leaving your liver your stool will be light colored or white.
is it mucus or your stool itself ???iron should make it turn black I would consult your Dr
Hmmm good question "bump"