Please consult a gen surgeon physically.

With constipation and laxative use behind it, this burning is almost always a small anal fissure or early piles rather than any infection. Hard stool tears the sensitive anal lining, and then every motion re-irritates it, which is exactly the burning you describe. Two days is early, so it usually heals fast if the stool is kept soft. Bleeding, a painful lump, or fever would change the plan.

Sitz bath

kindly do connect and consult with me for better treatment plan and advice on your case via PRACTO app

A proper consultation is needed to assess and guide treatment.

Can help you, kindly consult and provide detailed history for proper diagnosis and further management

Any history of fresh blood while passing stool? Any swelling around anus?