Differential Diagnosis for Abdominal Pain with Loose Stools and Typhidot IgM Positive but Widal Negative

• Single Most Likely Diagnosis
  • Typhoid Fever: The presence of abdominal pain, loose stools, and a positive Typhidot IgM test strongly suggests typhoid fever. Typhidot is a rapid test used for the diagnosis of typhoid fever, detecting IgM and IgG antibodies against the O and H antigens of Salmonella Typhi. The negative Widal test does not rule out early typhoid fever, as it may take some time for the titers to rise.
• Other Likely Diagnoses
  • Gastroenteritis: This could be due to viral or bacterial causes other than Salmonella Typhi. The symptoms of abdominal pain and loose stools are common in gastroenteritis, but the positive Typhidot IgM suggests that typhoid fever is more likely.
  • Viral Gastroenteritis: Viruses like norovirus or rotavirus can cause similar symptoms. However, the specific positive test for typhoid makes this less likely.
• Do Not Miss Diagnoses
  • Intestinal Perforation: Although less likely given the information, any condition causing severe abdominal pain, especially if accompanied by fever and signs of peritonitis, could potentially lead to intestinal perforation, which is a medical emergency.
  • Appendicitis: While the symptoms could overlap, the presence of loose stools and a positive Typhidot test makes appendicitis less likely. However, it's a condition that cannot be missed due to its potential for severe complications if not promptly treated.
• Rare Diagnoses
  • Salmonella Paratyphi Infection: This infection can present similarly to typhoid fever but is less common. The Widal test may not be positive in paratyphoid fever, and specific tests for paratyphoid antibodies might be needed.
  • Yersiniosis: Caused by Yersinia enterocolitica, this infection can mimic appendicitis or gastroenteritis and is rare. It would not explain the positive Typhidot IgM test unless there was a false-positive result.