pain on right side of body associated with mediport disconnection

my mom was diagnosed with stage 4 cancer in her colon and also had a tumor, which is now gone thanks to the chemotherapy. from there they found a few spots on her liver and are treating it with a mediport that is on her chest on the left side. she has 4 hour long sessions of chemo and then is sent home with a pump for the next day and a half. the pain starts whenever she gets disconnected from the pump and it is almost always on her right side from her chest area/shoulder blade area all the way up to her head.

she's been the emergency room NUMEROUS time and the doctors send her home saying it is nothing. if it was nothing, there wouldn't be any pain, would there? yeah! her doctor doesn't seem to be much help at all and i've grown tired of asking him what it could be.

so if there is anyone out there that could help her, please do. i'm willing to try anything at this point to not see her in pain. 

thank you and God bless to anyone that reads this or offers advice.