A coconut water fast will alkalize and nourish him but it is sugary. Will also take care of his kidneys.
A lemon water fast will alkalize him and is not sugary. Add cayenne pepper aka siling labuyo.
Maybe he should take VCO some 4 tablespoons per day to help control his infections and give him energy and lubricate his colon.
Maybe all 3 in combination will do.