What causes yellow noisy watery poop in breastfed babies? i know its normal but i'm just curious why it's not solid & brown.

Breast milk: is the ideal food for babies. As such, most of it is absorbed in the GI tract, leaving little left over to form a solid stool. Color is dependant on the type of food ingested, how fast it moves through the intestine and the overall functioning of the gallbladder.

Newborn stools: The transit distance is shorter in newborns, and the transit time for stool from top to bottom, is shorter. The rapid transit results in a light colors, soft or pasty or seedy stool. This is exaggerated with breastmilk.