My toilet drips constantly from the soil pipe - I can't see underneath the pipe (it's near the floor) to apply leak repair putty. It has a flexible joiner at the toilet end which was also leaking but mended with putty.
Take out the toilet and replace the pan connector i.e. teh one that fits between the WC and the soil pipe. Putting repair putty will NOT cure the problem.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix toilets.