I went to a stomach doc and without even examining me ordered a colonoscopy, ultrasound cat scan and chest x-r?

Not such a big deal. Maybe your list of symptoms was severe enough to warrant those tests. He could be sued for malpractice if there's a record of your complaining of certain symptoms and him not running those tests and you end up ill. He had to have cause or insurance wouldn't pay. If you don't have insurance all the more reason he would only run the tests if he felt you needed them.