Hi Mervyn,
My old cat Rosie used to do that when she had poo stuck to her bum, she was long haired and sometimes a turd got stuck so she'd pull herself along and draw brown lines on the lino, which was lovely. Does sound like worms though, you don't need to get wormers from vets though, you can get drontal from vetuk or somewhere like that, I find them easy to administer (once I have actually caught the cat which is the hardest bit!)
Mine are indoor cats too, sometimes I feel guilty but when I see how healthy, happy, active and safe they are I usually feel better about it. Too many cats get run over, lost, shut in somewhere, hurt or poisoned these days, is a shame but times are a changing.
Hope you get your benefits sorted, I work on Emplyment Support Allowance for the DWP so if you need any advice PM me.
Jo