Ooops top right not left for the health pages...
Theres several things you can do, none of which will be very enjoyable but you've made the hardest step already, which is admitting you are dependant on the pills.
I know you don't want to talk to your GP or employeers but as you have been using the codeine for a recognised use you might be surprised to find they are more supportive than you expect. In any case I would ask your doctor for an alternate IBS treatment plan as long term codeine use is not a viable option really regardless of the addiction issues.
If you stop taking the pills cold turkey you can expect 3-5 days of acute withdrawal symptoms, think severe flu & hangover at the same time. If you do not wish to tell your employeers flu could be a good cover story... There are things you can do to mitiage the symptoms, see Health Pages top left corner for Thomas reciepe. If nothing else get some Immodium given the IBS issues already present.
You could taper your intake of the pills down instead but given the availability of codeine in the UK you would need the willpower of a monk to stick to that.
In the interests of being honest you will very likely suffer other problems such as depression for sometime after the acute WD is over, not want to put you off but its best to be aware I think.
I am guessing this is some sort of codeine?..being a nurse i do feel ur pain..support is a necessary part of recovery...loss of control to our DOC is part of the definition as far as addiction goes,,,it is imperative ur dr knows//or he/she will continue to RX them to u//cutting off supply is part of breaking this cycle..finding support of some type is also crucial...if u can not do this then ur chances of success go way down unless u r a super-being...addiction is a disease/can happen to anyone///dont let shame put u in the gutter....this crud only gets worse....u gotta let go
I'm not familiar with the med co codamol, but if it's anything like vicodin, you could try tapering. The one thing about tapering is it takes so much willpower. You have to set up a taper plan and stick to it. If you ever find yourself taking more than what your planned calls for, you should just go cold turkey. That is if it's a medication that you can go cold turkey on. You could also talk to your doctor as there are other medications out there that can help with withdrawals. Exercise as much as you can. It makes a world of difference. Also be sure to eat healthy and push the fluids to help flush the body. Support is huge and this forum is the place to get it. There are so many wonderful and caring people on here that will not judge. Post and read other posts. It really helps by keeping our motivation level high. Hang in there and if you need anything, please let me know! Best of luck!
Brian