My girlfriend just had her gallbladder removed last thursday. last night she noticed a hard lump on the right side of her abdomen.

Follow-up: Have her see the surgeon in a follow-up post surgical evaluation. It may be simple scarring at the site, etc. depending on if her Removal was open or laparascopically etc. It is important for the surgeon to follow-up at the least 1 week after the surgery anyway. best wishes.

Trocar site: If it's at a trocar site and not red/inflamed then it's normal, If not then consult your surgeon