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.
As I mentioned, irony informs the whole work because it is the necessary means of aggressing hypocrites. It is not therefore one of the techniques of satire, but, like the purpose of correction, is part of the essence.