An unusual cause of back pain

A previously well 10-year-old girl presented with 3 months of L5-S2 back pain. This had started insidiously while in Sudan and woke her nightly. She reported 5 days of constipation and urinary frequency but no neurological symptoms, fevers or weight loss. Her body mass index was normal and she was premenarchal, although had signs of thelarche. Cardiovascular and respiratory examinations were normal. Routine observations were unremarkable. She reported L5-S2 pain upon lumbar extension (not present on palpation). No neurological signs were elicited. Abdominal examination revealed suprapubic fullness, clinically thought to represent constipation, with no organomegaly. What differentials should be considered? What are the red flag symptoms to elicit? Back pain affects 17%–26% of adolescents yet specific diagnoses are reached in only half of the cases.1 Significant pathologies should be carefully considered …