Welcome to health care magic
It is really nice to hear from your side because you are a medical student and a future doctor and and i am happy that you are so keen in trying to corelate the findings , that is really the big quality that a doctor should have, any way in case of your father ,the ultrasound report of fatty liver may be related to his vague complaints of abdominal fullness and discomfort, constipation and loss of appetite in the sense that if he is having hypothyroidism
then his vague complaints may be due to that and hypothyroidism is known to cause dyslipidemia
which can cause fatty liver, more over hypothyroidism in advanced form can cause myocardial weakness leading to valvular regurgitation which can cause murmers. so you can get the following tests done like Thyroid function test, Lipid profile
, Liver function test and can also seek an endocrinologist's and cardiologist's openion . Regarding diet he can take fat free diets.
I hope you are conveinced now and also hope your father will also get well soon