What Causes Fatigue, Bloating, Constipation. Extremely Swollen Feet And Ankles?

My father is 87 and has had extremely swollen feet and ankles ( unable to wear socks or shoes) for past few years and more so over last few months. He has a sound heart, although has taken Monoplus for several years even though his blood pressure readings are excellent. He also gets very fatigued. He has not had blood or urine tests for kidney function. He has an excellent diet, does not smoke and is not over weight. He also has had increasing digestive complaints, bloating, constipation etc. Should he gave kidney function tests, and could his medication be a cause.