My honest answer would be YES it CAN.
I really dont know the actual longterm side effects, no one whos honest can guess or give a correct answer to that BUT I would say aslong as its done safely and sensible and the user doesnt rush into things and gets over confident and knows their limits than they shouldnt be a issue.
However, I aint saying that eveyone who has ED who practices Penis Enlargement has fucked up cos they went in too hard or did too much ect.
Maybe some genes have a part to play? enviroment? I certainly feel lifestyle does.
Its an area of penis enlargement that needs looking into, perhaps someone could oneday make a large study on it and go into various directions so one can see how and if ED occurs from Penis Enlargement and if so whos a candidate?
But for now the short answer is YES you can get ED but I would say aslong you do it sensible and dont rush you shouldnt.
Also bare in mind, we all sometimes get erection problems, this is caused through many factors [yet another wall they will make it hard to complete a study like I said above] such as stress, medication ect.