Thanks for writing to us.
The bump on the lower rib is suggestive of a hematoma
formation in the area which might have developed after a soft tissue injury
or a fractured rib in the area. You need to have rest and take a mild pain killer for relief.
I hope this information has been both informative and helpful for you. You can consult me again directly through my profile URL http://bit.ly/Dr-Praveen-Tayal
Dr. Praveen Tayal