I've used subs and didn't taper and escaped w/o withdrawals. But the consensus is you will have them if you use them for 5 days. I used them for 6 or 7 days to come off tar heroin and experienced no physical withdrawals. I can only speak to myself for that matter.
This thread's title commanded my attention because morphine was my main thing before h. I never was physically so dependent I experienced WD's, but from what I understand, in most cases, they are protracted compared to h, lasting a couple weeks up to a month, however they are less severe. Once again, I inexplicably never had to deal with those despite a consistent and escalating amount of abuse.
I have to dissent from what the overall opinion seems to be here: I think you should wait to see what you're dealing with in terms of physical WD before seeing a Dr. for subs. They are expensive (on the streets or Dr's office), and, as mentioned above, often have their own set of WD's, albeit less severe. But why add them to the mix when you may not need them. Admittedly, I'm doing a good deal of speculation seeing as I don't know your typical dose, length of addiction, or type of morphine. I always did the ms contins - I miss the days of being able to simply chew up two of those and be set for the night. So simple compared to the junkie life style. Morphine was definitely my first opiate love, my honeymoon all opiate-addicts cherish like the warm early days spent with a first love. And I'm comfortable speaking for other opiate addicts when I say that.... if they are your DOC and you bypassed this phase, I am truly and very sorry for you.
If you find the time, and aren't feeling terrible give us an update outlining the nature of your use/abuse, as well as keep us updated with your progress and hopefully your eventual success. Best of luck.
PS: Regarding the subs: most of the people here are addicts or at least experienced (myself included), which gives them an unofficial authority of sorts. And not to say addicts can't be caches of information, and/or highly intelligent. In some ways your run-of-the-mill junkie will be privy to first-hand experience with opiate addiction many doctors will not have (I know, I know: there are doctors with habits of all kinds, but I think it is fair to assume many do not). However, I would really urge you to consult a doctor or some form of medical professional at least - even if you plan on buying them in an alternative manner. There is no substitute for professional advice, yet your personal judgment rivals, if not trumps it, in importance, so it comes down to you in the end. Rarely, doctors can get it wrong, so hound them with questions so you can make the most informed decision. I'm sure this is all common sense for you, but had to say it, a safety net/disclaimer of sorts.