Hi, Thanks for using the HCM.
Hi pus is due to infection and it may be due to diarhoea or by external infection.Before this you told your anus was bit sore it may be due to anal fissure
or due to some local infection. It may be due to fistula or chrons disease for which proper examination and investigations are required.
Pus shoud be drained out for management and should have antibiotic coverage. So for the proper management kindly consult your surgeon.
Hope I have answered your query. If you have any further questions I will be happy to help. Thanks get well soon....