Constipation and hemolytic uremic syndrome

Pediatr Nephrol. 2024 Feb;39(2):603-607. doi: 10.1007/s00467-023-06093-8. Epub 2023 Jul 20.


Background: Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome (HUS) classically presents with diarrhea. Absence of diarrheal prodrome increases suspicion for atypical HUS (aHUS). Inability to obtain a fecal specimen for culture or culture-independent testing limits the ability to differentiate STEC-HUS and aHUS.

Case-diagnosis/treatment: Our patient presented with abdominal pain and constipation, and evaluation of pallor led to a diagnosis of HUS. There was a complete absence of diarrhea during the disease course. Lack of fecal specimen for several days delayed testing for STEC. Treatment for atypical HUS was initiated with complement-blockade therapy. PCR-testing for Shiga toxin from fecal specimen later returned positive. Alternative complement-pathway testing did not identify a causative genetic variant or anti-Factor H antibody. A diagnosis of STEC-HUS was assigned, and complement-blockade therapy was stopped.

Conclusion: Diagnosis of aHUS remains a diagnosis of exclusion, whereby other causes of HUS are eliminated with reasonable certainty. Exclusion of STEC is necessary and relies on testing availability and recognition of testing limitations. Diarrhea-negative STEC-HUS remains a minority of cases, and future research is needed to explore the clinical characteristics of these patients.

Keywords: Atypical HUS (aHUS); Hemolytic uremic syndrome (HUS); Shiga toxin-producing Escherichia coli (STEC).

MeSH terms

  • Atypical Hemolytic Uremic Syndrome* / complications
  • Atypical Hemolytic Uremic Syndrome* / diagnosis
  • Atypical Hemolytic Uremic Syndrome* / therapy
  • Complement Pathway, Alternative
  • Constipation / complications
  • Diarrhea / diagnosis
  • Diarrhea / etiology
  • Escherichia coli Infections* / complications
  • Escherichia coli Infections* / diagnosis
  • Escherichia coli Infections* / drug therapy
  • Humans
  • Shiga-Toxigenic Escherichia coli*