My Father In Law Age 68 Had Lung Cancer 3

My father in law age 68 had lung cancer 3 years ago went though treatment quite successfully. He is also a diabetic. Now he has been told through his doctor with a sonogram that he needs to have his gall bladder removed. Has been retaining fluid and his feet are quite swollen. He has been recently also having terrible leg cramps. He was given a diuretic and potassium. Any of the symptoms make any sense?
Also can gall bladder surgery be done with laproscoptic surgery?