What is the Bottleneck Effect? — Definition & Examples

You eat food at a gross restaurant and come down with a case of food poisoning! E. coli in the food makes you sick, and the doctor prescribes you antibiotics for two weeks to get rid of it. However, you feel better after just one week of antibiotics, so you decide to stop taking them. One week later, you feel sick again. You're prescribed more antibiotics, but they don't seem to work. What happened?