The immediate assumption for Jacob's condition would be acute appendicitis, but I find the phrase 'familiar ache' particularly troubling. It's also happening at a time when Andrew doesn't need such a severe distraction.
It's the things you don’t know that trip you up. Neither Enrico nor Andrew recognize each other as primary players, but how long will it last when their destination is identical? It's pretty clear now Milos was trying to say Alvarez. On Enrico's part, he is unaware of the intricate trip wires on Finch's accounts, and counting too much on the combined security of Swiss banking and cryptocurrency.
The game is notching up.