The elder scrolls 4-Oblivion

Does anybody knows how can i make the quest,arrow of extrication, of the thives guild? also i have some problems with three illnesses

make the quest of thieves guild?are u trying to ask how to start the thieves guild mission??in that case i think u need to go meet some dude near imperial city dungeon or something check out the walkthroughs

Have you tried cure disease potions?

For any quest problems search the quest name on uesp.net, like so: http://www.uesp.net/wiki/Oblivion:Arrow_of_Extrication