We were busy celebrating our friendship with wine and song, when Enkidu fell sick.
I think the gods put something in his food. Enkidu knows it is punishment for touching the gods' trees. He is ashamed to die in bed and not in battle. He curses the day he ever set foot in the city. He curses Shamhat for ever making him want civilisation. Shamhat asks him if that is fair, as she only ever gave him good things. Enkidu apologises. He accepts the will of the gods.
Every day he grows sicker and more in pain. And finally Enkidu dies.