OK, so think about this:
SRIs, Serotonin Reuptake Inhibitors, cause nausea, bloatin and gas. They cause ugly stomach upset combined with very acidic stomach.
Caffeine is an base. It reacts with acid in the stomach and produces salt and water. That's how I understand it, remembering from Chem 111.
Taking SRIs gives me pain all day. Drinking coffee makes me feel better. Hey!