Hi, 

18 months ago my dad was diagnosed with Primary squamous cell carcinoma of the parotid glandwhich is a rare and aggressive malignancy cancer (1 in 100,000) the operation which was a total parotidectomy, a mastoidectomy and a selective neck dissection with local flap coverage was a long operation, but they removed 99% and the 1% he had radiotherapy. It has now confirmed that the cancer had gone. 
 

A few months ago he started to get bouts of really bad pains after eating, doubled over, being sick and couldn't physically lay on his front which meant no sleep. He often gets a bit of griping when he eats (certain foods seem to trigger) but the bouts of extreme vomiting and pain are few and far between. We've been told that this "issue" will not be connected to his tumour, but they've taken samples of his stools, he's had a colonoscopy (all come back fine) along with a CT scan. They've only found some inflammation in the bowel, but he is now waiting for results from a PET scan on Saturday. Are PET scans looking for cancer and are they doing this because they are looking for cancer cells? As as far as I'm aware PET scans are only used for cancer, right? 
 

Any advice would be appreciated x