CEA @ 200

A CEA of 200 is extremely serious.  It's a run, don't walk kind of number - which depending on  manufacturer "brand" would be 15 or 30 - that needs immediate follow ups.  It might not be colorectal cancer, a lot of solid cancers can elevate CEA but it is literally rare to not involve cancer at that CEA level.  I'd ask for the names of insurance managers with corporate responsibility because this sounds like a situation that could soon be a reportable situation to the state insurance department for life endangering obstruction and willful negligence.

You could build your infomation with other cancer (related) markers, DIY - in asia it's common to do a  gang of tests with 5 to 12 markers at a whack, including CA19-9 and AFP, markers that cost us under $20 to add on. LDH is a cheap liver marker that often has important CRC information too and we control for long term inflammation with ESR.  We actually usually order our own blood tests these days, because its more convenient, cheaper and quicker - never an argument. We  get next day service ordering for ourselves with one local lab, but LEF was easiest to start in the US.  Although not standard markers for CRC (they will resist), CA19 and AFP are more important right now for us and have been useful, CA19-9 from the start and AFP ater a few years was rising across a year or more interval.

A CT scan is the standard first CRC scan.  If insurance delays you and money was extremely tight, I might even do a flat (2D), really cheap-o X-ray out of pocket for speed and privacy with 1/50 the radiation of a CT scan, because in all likelihood you're dealing with a  serious, house on fire situation but we use extra blood tests and cancer markers.

I did immediately start reading the LEF, Life Extension Foundation articles on cancer, surgery, and CRC when my wife was first diagnosed. I immediately told her to start most of the recommended supplements and cimetidine. 

We followed a lot of their nonstandard advice additively, and added on more, to help her through surgery, chemo and cancer.  She's still alive and doing pretty well, when all other patients like her for our doctors' experience, are all long, long dead.  

Truth to tell, we totally wired out the insurance company and any backwards doctors on extra steps for the first year and paid it ourselves. Life is too precious for advice that is incomplete and obsolete in reality.  Also the extra information meant we could anticipate problems sooner and better, get extra chances on making the chemo work and to get a hard-to-get second surgery, "guide" the doctors thinking somewhat when they wanted to write us off, and push or fire as necessary.