I work for a L.A Cheryl and am very familiar with the policies you mention- they also seem to change them at will and not properly inform people where I work. It used to be you can self-certificate up to 7 days and then you need a medical certificate. Now, it is the first 3 days. Once you do hit triggers of their determined policy, they send you to the Occupational Health Dept (supposedly an independent medical evaluation, but as the L.A pay their bills and work for them, I fail to see how this is "independent" or impartial.
I suffer from a condition that causes some swelling around my brain/spinal cord/back of eyes and I get horrific headaches from extra pressure (think bad migraines + 3), pain that is indescribable to some people and I also experience vision disturbances and so on, so I have exhausted our sickness absence policy to the max and have been put through various monitoring periods because I hit the "headache" trigger very quickly in any period (duh). However, much to my employers disappointment there is nothing that they can do- I am covered by the DDA in this instance and I regularly satisfy OHD evaluations and mostly control this thing with medication- doesn't mean they don't stop going after me though! It's caused a great deal of stress to me over the last few years as it's ongoing, but my view is that as long as the sickness is genuine and you are properly certificated and your normal performance is above reproach, there won't be a problem.
I have had to argue that although I have time off for the above, I don't get "usual" illnesses like some people do generally speaking, like a bad back or colds & the flu and as they agree that they cannot fault my performance, time-keeping, motivation etc, they have to act under the Capability Procedure which is another policy altogether. In my case I have successfully argued for my sick time to be a percentage of "normal illnesses" and "my condition related illnesses" which they put at 25 days p/a- I made sure to get this in writing!
The big problem with local gov. is that unless a specific circumstance fits into their policy, they kinda lose their heads and forget to think outside of the box sometimes, you would think with the number of employees they have they would figure this problem out, but that seems Waaaaay beyond their remit!
Sheril.