Carol, it's important for a patient to drink LOTS of water after the MRI, to help clear the contrast material. I also don't take diuretics for 3 days prior to an MRI, as they tend to elevated the creatinine. If out of normal range, they can't give the contrast. So the fact that he had the MRI with contrast tells me that his kidney function was okay enough for them to do the scan.
When he wakes up, push water. If he's still having pain by Mon., give a call to his doctor or go to the ER.
This past Mon., when I had 2 different contrasts for an MRI and a chest CT, it tore up my stomach. I had been fasting since midnight the night before (later found out I could've had breakfast) until around 4 PM. Starving, I went to the cafe, which was about to close, and grabbed a blueberry donut and coffee. An hour later, when I got home, everything I'd ingested went right through me. I continued to drink water and by the next day I was fine
Yesterday afternoon, I had another CT with contrast and had no problems. The trick is to drink lots of water after the scan.
The pain he is experiencing could be from his liver tumor.
Hugs,
Connie