I totally disagree with your doc's statement. By the time it burns, lotions/creams, etc. won't help. The damage to your skin is done and only time and patience will heal it. When I was trying to describe this to the doc (years ago), I asked him if he would, as a doctor, advise a patient to go to the beach (think hot sun, Florida) in the middle of the day when the sun was at it's hottest, and lie out there for a few hours without any sunscreen. "Of course not" he told me. Then why is radiation any different? Now, you can't have lotion/creams on DURING a treatment BUT......you can and should slather yourself after each treatment and in between. Don't skimp on it and pay extra attention to the anal area itself. Don't think that by 'protecting' the tush cheeks that you are somehow 'protecting' the anal opening....WRONG!
There are a few things you should know about radiation.
1. Radiation dries the skin
2. Radiation thins the skin
3. Make sure when you have your treatment your skin is clean and free of any creams or lotions. Many creams/lotions contain metallic substances and you will burn VERY badly if you have this on your skin during treatment. My analogy......think of a metal spoon in a microwave!
4. Wash with a glycerin based soap from the waist to the knees (or there abouts). Although you may think that soaps like Ivory are pure and 'gentle' they aren't. Glycerin has been proven to be the best substance in keeping moisture in one's skin. Remember, radiation dries the skin all by itself....no need to add regular 'gentle' soap to only make it worse.
5. Unless specifically told to do it, don't use steroid creams such as hydrocortisone creams. They also tend to thin the skin with long term use.
6. There are three areas of the body that burn worse than others. They are the: nipples, lips and the anus. These areas need to be protected more than usual when exposed to radiation. ( with pelvic radiation only talking about the anus)
7. Radiation will also tend to cause problems for the bladder. Unless otherwise told not to, have your treatments done with a full bladder (doesn't have to be uncomfortable). This also helps to push the intestines out of the field of radiation....helping to minimize damage to that area.
8. Radiation AND the chemotherapy are irritating to the colon and killing off the 'good' bacteria that are necessary for digestion. Consider taking probiotics 1-2 times a day. You will never (during treatment) get those bacteria levels to 'normal' but you will hopefully help keep problems at bay.
9. Keep yourself hydrated....drink water, juice...basically anything you want but STAY HYDRATED. You will feel better and hydrating may help minimize internal damage from the treatments.
10. Check the ingredients on any creams/lotions that you use. Most contain alcohol and alcohol dries the skin. Since radiation, by itself, dries the skin, no need to add another product that will only exacerbate the problem.
11. Stay on a low fiber diet. Eating high fiber foods are hard to digest and will lead to diarrhea. Last thing your anus needs.
For females, you should know that radiation will almost certainly cause vaginal scarring/stenosis that is very difficult to correct if you allow it to happen. My first rad onc was a total jerk BUT...he did warn me about this problem. Winked at hubby and told us we should either be having sex 3-4 times a week during treatment to stop adhesions from forming OR use a dilator. If you wait until after treatments are done, the scar tissue is already formed and much much more difficult to 'break' or stretch. Most women go through menopause due to the treatments and because of the lack of hormones, you should talk to your doctor about getting something like Premarin vaginal cream. Use it both externally and internally. SImply using something like K-Y jelly won't help with the dryness and lack of elasticity.
It may all sound like a lot to remember and impossible to implement but remember that treatments are only for 6 weeks. Please don't wait for symptoms to surface before trying to 'fix' them. Be proactive....head off symptoms before they rear their ugly heads.