Weight Gain in Stage 4 of COPD

My husband has Stage 4 COPD.  He sleeps all the time and he hardly eats anything maybe a total calorie count of 200.  However, he keeps gaining weight instead of losing weight. He gained 10 pounds in two weeks. Could there be something else wrong with him, or is the one of the symptoms of this Stage?  Everything I have read says he should be losing weight.  He does not complain of any pains and he is not swollen in his extremeties.  He does not have bowel movements and he urinates 3 to 4 times a day.