C.F.
My daughter had procedures called VCUG's which is basically a contrast that was injected into her bladder while she was awake through her vagina so they could get a good look at her bladder. She was born with a cyst on her bladder and had some plumbing issues that were causing reflux into her kidneys. She started having the VCUG (and about 10 times until age 6) and a ultrasound starting at age 1.
They used to give her a calming medicine on her pacifier to keep her calm. She then had two surgeries after that where she had to fast the night before. Sometimes they allow a clear diet but you will get those instructions from your doctor.
My youngest had her tonsils out at age 2. She had to do the fasting the night before too. To keep her still they gave her a medicine called Roxyset(sorry spelling might be wrong) it kept her knocked out most of the day after the surgery.
If you are going to a Children's hospital they have activities to keep your young one busy. Just try not to eat in front of them.
They are not allowed to eat because if there is sedation involved they could vomit into their lungs which can lead to complications and pneumonia.
My youngest didn't have a liver biopsy but a bladder biopsy which I am sure is just as painful. Recovery time after a procedure like that is usually one to two hours. You will be brought back to recovery to see your child and be prepared. It isn't easy seeing your child hooked up to machines and sedate.
My advice is bring a favoirte toy. Or you child might find a toy there. My oldest took a plastic ear of corn into surgery with her and came out still holding it lol!
The hardest part will be for you having to go into and letting go of your child for the procedure. At our Children's Hospital you are allowed to wait in the holding area with them. The internet can be both good and bad for you. Do NOT let it drive you insane! This biopsy will hopefully give you some answers you are looking for. Good luck to you!