Fluid Build Up in stomach after removal of cancer in colon

My father had a dime size caner in his colon and had surgery through his stomach to have it removed. After he was released from the hospital we noticed his stomach was getting bigger by the day. After about 2 weeks it (his stomach) has stretched in size and was bloated and hard. His stomach had formed a bright red color around the staples on the skin and was warm to the touch. We made an appointment with the surgeon and he said the fluid build up was normal and he had them (nurse) drain his stomach. They put a needle in his stomach and drained all the fluid. His stomach went down in size significantly. Well about six weeks later his stomach again is full of fluid again and it’s big, stretching out to the point of it being painful. His doctor claims it’s normal and should go down within time. I am worried. Is this normal after surgery? What could be the cause of this? Will he always have to have it drained? Please, any comments, suggestions advice will be helpful.
Thanks!!

[HelpMyDad]

the fluid build up is actually under his skin and outside of his organs, when I said the drained the fluid from his stomach I ment to say they drained it from his belly. Thanks.

[Sir Vincent]

I had a fluid buildup only a day or two after my surgery, and while not as long away as your dad, I've yet to have another. Of course, they said I just had an obstruction or some blockage. But having known the pain myself, send your dad my condolences.

And I think everyone understands the context here to mean it was drained from the belly.