Laravel 5.1 - Return to edit page

i'm writing a resource controller, and i have a problem with edit method.

i inserted a validator form, and if there is a error return to edit page with messages, but RETURN doesnt work good!

public function update(Request $request, $id)
    {
       $rules = [
            'title' => 'required',
            'content' => 'required',
            'image' => 'required',    
        ];

        $messages = [        
            'title.required' => 'Campo titolo richiesto',
            'content.required' => 'Contenuto richiesto',
            'image.required' => 'Campo immagine richiesto',
        ];

        $validator = Validator::make($request->all(), $rules, $messages);

        if ($validator->fails()){

         return redirect('admin/article/edit' , $id)->withErrors($validator);   

        }else {


            $s = new Article;



                $visible = (isset($_POST['visible']) == '1' ? '1' : '0');

                $data = array(

                'title'          => $request->get('title'),
                'slug'          => $request->get('title'),
                'content'    => $request->get('content'),
                'image'            => $request->get('image'),
                'user_id'        => $request->get('user_id'),
                'category_id'    => $request->get('category_id'),
                'visible'        => $visible,
                );



             $s->where('id', '=', $id)->update($data);
             return redirect('admin/article')->with('message', 'Articolo aggiornato con successo!');


         }
    }

It return to:

admin/article/edit/5

NOT to

admin/article/5/edit

How can i fix this issue? thank you for your help!

PS: $id work well, return my id edited

via Chebli Mohamed