722 Solitary rectal ulcer syndrome: a rare presentation in paediatrics

Abstract

<h3>Background</h3> Solitary Rectal Ulcer Syndrome (SRUS) is an important but often delayed diagnosis with a prevalence of 1:100,000 people per year. It is rare in children. Manifestations include rectal bleeding, pain, tenesmus and, occasionally, rectal prolapse. 26% are asymptomatic. Classically, sigmoidoscopy reveals ulceration within 10cm of the anus and histology demonstrates mucosal layer thickening with crypt distortion and lamina propria fibromuscular obliteration. It is, however, a misnomer as only 20% have a solitary ulcer with the remainder have lesions ranging from hyperemic mucosa through to broad based polypoid lesions. It’s not uncommon that patients are initially misdiagnosed as constipation or inflammatory bowel disease (IBD). The mainstay of treatment includes biofeedback though some patients require surgery for rectal prolapse. Whilst the aetiology of SRUS remains unclear hypothesised causes include ineffective straining and/or uncoordinated puborectalis contraction increasing intra-rectal pressure and causing ischaemic ulceration or local vascular trauma due to intussusception. <h3>Objectives</h3> To highlight awareness of SRUS and how it can mimic constipation and IBD. <h3>Methods</h3> A 9 year old female patient presented with apparent constipation, resistant to laxatives. Initial abdominal pain and passage of a type 2 stool weekly progressed to rectal bleeding and passage of mucus. A later more in depth history also identified straining and tenesmus. Over several months she was treated with escalating doses of Movicol, Sodium Picosulfate, Liquid Paraffin and Klean Prep. Treatment compliance was an issue initially. Ileocolonoscopy with rectal retroflexion detected a macroscopic solitary rectal ulcer and only isolated diffuse rectal inflammation on histology. Her faecal calprotectin was normal. A diagnosis of inflammatory bowel disease was questioned but treatment with Mesalazine foam enemas was unhelpful. She also developed dysfunctional voiding during the course of treatment with significant bladder retention. Non-compliance with intermittent catheterisation due to significant anxiety led to insertion of a suprapubic catheter. Further investigation with a colonic transit study was performed due to her ongoing requirement for high dose laxatives and found markers pooled in the rectum. A diagnosis of rectal dyssynergia/dysfunctional elimination was reached. She responded to suppositories which later weaned following successful use of Botulinum toxin despite her anorectal manometry not showing high resting pressures. <h3>Results</h3> SRUS is an important comorbidity in children presenting with constipation on a background of rectal dyssynergia/dysfunctional elimination. Our patient’s significant anxiety has contributed to her dysfunctional elimination and she has ongoing CAMHS involvement so that biofeedback can be initiated. The absence of conclusive histology perhaps delayed a diagnosis being reached and her initial non-compliance with treatment was likely to be a significant contributing factor too. The key to diagnosis here was reviewing her histology in the context of her initial presenting features including passage of blood and mucus alongside straining and tenesmus. <h3>Conclusions</h3> Whilst SRUS is a relatively uncommon diagnosis seen in the paediatric population, good history taking and consideration of clinical features is key to its diagnosis, even if histology is not confirmatory.