The Seder Hayom (Rabbi Moshe ben Machir, 16th Century, Tsfat) makes a remarkable statement regarding the Beracha of Asher Yasar. He first writes that one should reciter the Beracha carefully, word by word, having full intent and concentration on the meaning of the words, which are a praise to the perpetual kindness of Hashem who enables our bodies to function by expelling wastes. If not for this ability, no sum of money to pay the greatest doctors could help a person, and he would die. Hashem formed the various cavities and compartments in the body to retain the beneficial nutrients and expel the harmful waste, so that we could live in health and stand before Him.
He continues and declares that one who is scrupulous in reciting Asher Yasar with this Kavana will never get sick his entire life and will not need the services of doctors or their treatments.
