Thank you for your query on Healthcare Magic.
Hard painful bumps on the healing scar could be due to secondary infection with abscess
formation or due to hypertrophy of scar know as keloid.
Scar has to be examined by the surgeon who have done suturing.
If there is infection, it has to be treated with a course of antibiotic.
If there is keloid formation, steroid
applications will help to decrease the size of bumps.
Consult the doctor for further examination.
Hope I have answered your query.