I can understand your concern.
Widal is to find out if you are having the disease at present and in it there are some specific antigens are detected.
However, IgM and IgG are tests to detect the antibody produced by out body and from that we can get a idea if you are a chronic sufferer of thyphoid or a carrier and since how long you are harboring it. It is not a replacement for Widal.
Consult a MD physician for further evaluation and management.
Dr. Anil Kumar Jain.
WIDAL is a screening test and IgG and IgM are more like advanced diagnostics. It is certainly not a replacement.
In India, we have endemic of Typhoid and sometimes doctors can ask for IgG and IgM to be more specific in trying to understand complicated illnesses.