Bile salts give stool its characteristic brown color. If there is decreased bile flow caused by a condition affecting your gallbladder, liver, or pancreas (such as cholecystitis, gallstones, giardia, hepatitis, chronic pancreatitis, or cirrhosis), there may be a lack of bile in stool, making them pale or clay colored.
The writer uses irony in the passage with the sense of purposes to it. This purposes includes, criticizing the adults, to sympathize the children and also to create a tragic situation in the passage. Firstly, the writer uses the technique irony to criticize the adult.
dramatic irony: a discrepancy between what the speaker says and what the author means; the unexpected fulfillment or reversal of a character's expectations; a device by which the author implies a different meaning from that indented by the speaker in a literary work (ex: the closing line of William Blake's The Chimneysweeper: So if all do their duty they need not fear harm.)