My brother has stage lV lung and liver cancer. He had lost his appetite almost a month ago. When I went to see him, he had also lost over 62 pounds and was only drinking Boost. I had him rushed to the local hospital where a PEG was inserted. Now, his abdomen is extremely extended and he is in constant pain. A CT Scan of his chest was done and it was negative, along with a paracentesis. However, no fluid was withdrawn from his abdomen. What could be causing his abdomen to swell now?