Gruesome Guts (S01E06)

Poo, pizza, and yucky germs! What causes us to poo, and what happens during digestion? Who was Louis Pasteur, and what contributions did he make? Mark shows up at the studio in agony from stomach cramps and turns to The Shrinking Scientists for answers. It’s their biggest challenge yet, as Dr. Sensible, Professor Small, and Junior prepare to soar up Mark's nose to uncover the source of his discomfort.