If your immune system is compromised, it is possible your body would not be able to send the resources necessary to fight off the infection that you already have immunity to, therefore there is some possibility of a reoccurring illness in an immuno-compromised individual.
A or B, those are important to learn later in life once you live on your own.
Diverticulitus causes lower left pain
You get to breath clean air
there are no bad smells