Nic,
Bummer about the rash. We all have gone through that.
I second what Rob has said. I also use the Equate Diaper Rash Relief cream from Walmart.
As you are in the UK, that brand may not be available to you. What is important is that this diaper rash cream contains 40% zinc oxide.
Zinc oxide cream forms a thick protective barrier on the skin. It also is a natural antibacterial agent. I am double incontinent (bladder and bowel) and have had NO rashes since I began using this product. The downside is that your diaper area will be white due to the cream.
Most diaper rash creams will contain about 11% zinc oxide. Try them and see whether they work for you. 11% often is adequate for urinary incontinence. You should renew it mid-way through your day, after you wash. If you are bowel incontinent or cannot wash and change mid-way through your day, choose a barrier with a higher percentage of zinc oxide as it will form a barrier that will last longer.
Here are some other anti-rash tips. Wash thoroughly with water at mid-day. Skip the soap while you have an active rash as it may be drying and irritating to the skin. Pat but do not rub the rash area. At other changes at least use cleansing wipes.
Change your diaper (nappy) more frequently while you have a rash.
After at least one diaper (nappy) change, try to "air out" for 30 minutes or more. You may need to sit, without a diaper, on an absorbent pad during this time.
If you are wearing all plastic-backed diapers, you may wish to consider wearing at least one breathable diaper each day for more air circulation. If the rash continues you may need to change over to breathable diapers.
If you are using vinyl plastic pants, you may find it helpful to change to PUL pants (polyurethane laminate) which are waterproof but breathable.
If these methods to not cause the rash to clear up, you should see your physician.
Good luck,
--John
You should buy some rash cream in your pharmacy and if it doesn't help, then go visit a doctor because on the long-run it may really be exhausting. Good luck with fixing that!