Post-renal obstruction is an unusual cause of acute kidney injury (AKI) in the paediatric population, with haemolytic-uraemic syndrome being the commonest cause of acquired AKI.^1–3 We present a case of a two year old with AKI secondary to severe chronic constipation.

The patient presented with abdominal pain and bloating on the background of chronic constipation and Fragile X syndrome. Initial treatment was for constipation. However, after clinical deterioration and concerns on clinical examination an abdominal film was obtained (Figure 1).

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Abstract G390(P) Figure 1

Abdominal x-ray

This shows a large mass in the right iliac fossa, possibly arising from the pelvis, leading to suspicion of a malignant diagnosis. Biochemistry results showed acute kidney injury with a creatinine of 166 µmol/L. Further investigations showed a raised CRP. Urine and blood cultures grew Enterococcus faecalis. The patient was started on intravenous antibiotics and fluid restricted.

The next day he was transferred to a tertiary renal unit where ultrasound investigation showed the mass to be a large bladder, combined with bilateral hydronephrosis. A likely diagnosis of constipation causing post-renal obstruction was made and after catheterisation and faecal disimpaction the patient improved, (Figure 2).

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Abstract G390(P) Figure 2

Creatinine over time

A repeat ultrasound showed improvement in the hydronephrosis and subsequent MRI scanning demonstrated a normal spine and a large bladder with no mass/lesion causing bladder outflow obstruction.

Constipation is a rare, but previously documented cause of acute renal injury.⁴ This case further demonstrates the need to have an open mind to rarer consequences of common conditions and indeed, diligence in investigating these as a possibility.

References

1. Williams DM. Acute kidney failure, A Paediatric Experience Over 20 years. Arch Pediatr Adolesc Med. 2002; 156:893–900

2. Moghal NE. A review of acute renal failure in children: incidence, etiology and outcome. Clin Nephrol. 1998; 49(2):91–5

3. Shaheen IS. Acute renal failure in children: Eitology, Treatment and Outcome. Saudi J Kidney Dis Transplant 2006; 17(2):153–158

4. Barrett MJ and Macken S. Chronic constipation causing obstructive nephropathy in a delayed toddler. BMJ Case Rep. 2012 Jun 14;2012. pii: bcr0220125902. doi: 10.1136/bcr.02.2012.5902