Left side pain with abdominal distention - 1255410

Hi all, I'm new to this site.
My mom diagnosed in August with stage 4 adeno, has recently ( 3 weeks ago) taken a turn for the worst.
She right now has extreme pain on the left side rib area with some swelling and abdominal distention.
She's having a hard time eating because she feels pressure in the abdomen area. She does get a small bit of relief after passing gas and going to the washroom. Her abdomen is very hard from the belly button to under the breasts. Under the belly button is normal. What coul this be? Is it possible the cancer has spread to the abdomen? Would that be causing left side pain?

Thank you!