Doctors diagnose typhoid by detecting the presence of S. typhi via blood, stool, urine, or bone marrow sample. Symptoms Symptoms typically begin 1–3 weeks after exposure to the bacteria. The two main symptoms of typhoid are fever and rash. Typhoid fever is particularly high, gradually increasing over several days up to 104ºF. The rash, which does not affect every person, consists of rose-colored spots, particularly on the neck and abdomen. Other symptoms can include: diarrhea loss of appetite bloating nausea weakness abdominal pain constipation headaches