Hello
Welcome to health care magic. I really appreciate your concern.
Looking at your description it might be related to any of these conditions
1. hemorrhoids
2. Fissure or fistula in Ano
3. Infected anal gland
4. Perianal abscess
Blood mixed with pus is a matter of concern and it may lead to serious complications.
In my opinion you should immediately consulta
general surgeon for physical examination and series of investigation like blood for hemoglobin, CBC, CRP, ESR, liver function test and stool test.
You may require a course of action preferably ofloxacin and ornidazole/
metronidazole group of drugs under medical supervision.
Meanwhile maintain good hygiene, clean it with antiseptic soap or solution and apply antibacterial ointment like
povidone iodine or soframycin.
You should avoid
constipation by taking laxative or stool softeners.
You can apply
local anaesthetic ointment like lignocaine for pain relief
Sitz bath is advisable.
Hope I could answer your question, please feel free to ask for further assistance, I will be happy to help you.
Best wishes