i think i follow. if you have the code:
case REPORT_PATIENT:
displayPatient();
break;
in the middle of a switch block, and now highlight the red bits:
case REPORT_PATIENT:
displayPatient();
break;
as a single lump, and then press { you get a mess. as a comparison, with the same block highlighed if you press / then all 3 lines are commented out, even though you have only partly selected lines 1 and 3.
bonus, i have just discovered by doing this that / works on partly selected lines
if you are using the keyboard to select lines then this sort of partial selecting is normally easier than selecting the entire lines.