Since treatment depends on what the lump/swelling is, giving advice without knowing what exactly the swelling/lump us pointless.
If you feel your pediatrician's advise is not sound, or response to the treatment is slow, then please get a second opinion from a general surgeon.
Next Steps
confirm what the swelling is.
Health Tips
Taking advise online when none will be able to narrow down possibilities on the swelling: is not apt