Solitary Rectal Ulcer Syndrome

Overview

Solitary rectal ulcer syndrome (SRUS) is an uncommon, nonneoplastic disorder of the distal rectum characterized by mucosal ulceration, fibromuscular changes, and frequently mucosal prolapse or trauma from abnormal defecatory mechanics. It affects children and adults and is often underrecognized in pediatric practice.

Etiology

Abnormal defecatory behavior with excessive straining and paradoxical contraction of the puborectalis or pelvic floor muscles.
Internal rectal mucosal prolapse or intussusception producing repetitive traction and compression of the distal rectum during evacuation.
Direct trauma from hard stools or digital evacuation in chronically constipated children.

Pathophysiology

Mechanical stress and impaired microvascular supply cause localized ischemia, ulceration, and mucosal sloughing. Chronic injury leads to characteristic histopathology: fibromuscular obliteration of the lamina propria, glandular distortion, and hypertrophy/displacement of muscularis mucosae into the lamina propria. Dysfunctional pelvic‑floor mechanics perpetuate incomplete evacuation, ongoing straining, and persistent or recurrent ulceration.

Clinical manifestations (pediatric focus)

Rectal bleeding or blood‑streaked stools, often intermittent and variable in volume.
Mucus discharge, mucoid stools, tenesmus, and sensation of incomplete evacuation.
Chronic constipation and frequent straining; some children perform digital evacuation.
Anal or rectal pain; palpable rectal mass or visible mucosal prolapse on straining in some patients.
Presentation may mimic inflammatory bowel disease or other ulcerating rectal lesions, producing diagnostic delay without targeted evaluation.

Diagnostic evaluation

History and examination

Detailed toilet‑training history, bowel habits, straining, and history of digital evacuation.
Perineal inspection and digital rectal exam to assess prolapse, sphincter tone, and palpable lesions.

Investigations

Endoscopy (flexible sigmoidoscopy/colonoscopy): visualize solitary or multiple ulcers and obtain targeted biopsies.

Typical location: distal rectum, classically on the anterior rectal wall about 5–10 cm from the anal verge.
Number: often solitary but may be multiple or even absent (mucosal prolapse spectrum).
Appearance on flex sig/colonoscopy: solitary or multiple ulcer(s) with irregular margins and a fibrotic or granulating base; surrounding mucosal erythema and friability; associated polypoid or nodular mucosal thickening may be seen.
Other findings suggestive of mucosal prolapse/SRUS: puckering or tenting of the mucosa, visible internal prolapse or mucosal redundancy on straining, and contact bleeding.
Important caveat: lesions can mimic inflammatory bowel disease or neoplasia, so targeted biopsies are required for histologic confirmation.

Histology diagnostic features: fibromuscular obliteration of lamina propria, gland distortion, hypertrophied muscularis mucosae with displaced muscle fibers.
Physiologic testing when pelvic‑floor dysfunction suspected: anorectal manometry, balloon expulsion test, and defecography (video or contrast) to document internal prolapse or dyssynergia.
Exclude alternative causes of rectal bleeding with stool studies, cultures, or imaging when indicated.

Differential diagnosis

Inflammatory bowel disease (ulcerative proctitis, Crohn disease), infectious proctitis, ischemic injury (rare in children).
Hemorrhoids, rectal polyps, solitary ulcer from other etiologies, and neoplasia (rare in pediatric population).

Treatment

Treatment is stepwise, starting with conservative/behavioral measures and escalating to pelvic‑floor rehabilitation, topical/endoscopic therapies, and surgery for refractory or anatomically driven disease.

First‑line: Conservative and behavioral

Establish regular toileting routines with timed sitting after meals; avoid straining and digital evacuation.
Aggressive constipation management: high fiber diet, osmotic laxatives (polyethylene glycol) to maintain soft, regular stools.
Sitz baths, topical emollients, and local analgesia for symptom relief.

Pelvic‑floor rehabilitation

Pelvic‑floor physical therapy with biofeedback to correct dyssynergic defecation and retrain relaxation of the puborectalis during evacuation; effective in many pediatric cases when available.

Topical and endoscopic therapies

Topical sucralfate enemas or sucralfate paste to promote mucosal healing.
Topical steroid or mesalamine enemas may be trialed for local inflammation in selected patients.
Endoscopic interventions (argon plasma coagulation) for refractory bleeding or to ablate persistent granulation tissue in select cases.

Adjunct pharmacologic and procedural options

Botulinum toxin injections into the puborectalis or internal sphincter for documented spasm not responsive to biofeedback; may provide temporary relief of outlet obstruction.
Avoid prolonged systemic corticosteroids for isolated SRUS; use analgesics or stool softeners as needed.

Surgical management

Indications: failure of optimized conservative/biofeedback therapy, persistent severe bleeding, full‑thickness ulceration, or overt external rectal prolapse driving disease.
Procedures: transanal local excision or advancement flap for isolated ulcers; rectopexy or other prolapse correction for anatomically driven cases; resectional procedures rarely used in children.
Surgical decisions should be individualized in multidisciplinary discussion with pediatric colorectal surgery and pelvic‑floor specialists.

Follow‑up and monitoring

Regular reassessment of stool habits, bleeding, pain, and response to pelvic‑floor therapy.
Repeat endoscopy with biopsy reserved for persistent or worsening symptoms to reassess healing and exclude alternative pathology.
Continued reinforcement of bowel regimen and pelvic‑floor exercises to prevent recurrence.

Prognosis

Most pediatric patients improve with conservative measures combined with pelvic‑floor retraining, often achieving symptomatic relief and mucosal healing. Refractory cases related to overt prolapse or persistent dyssynergia may require surgery and have more variable outcomes. Diagnostic delays and continued maladaptive toileting behaviors increase chronicity and likelihood of invasive interventions.

Practical pearls

Consider SRUS in children with chronic constipation, rectal bleeding, mucus discharge, and tenesmus; maintain high suspicion to avoid misdiagnosis as IBD.
Early referral for pelvic‑floor physiotherapy and initiation of structured bowel regimens often prevents progression and reduces need for surgery.
Use anorectal manometry or defecography selectively to document dyssynergia or internal prolapse when planning biofeedback or considering surgical correction.
Coordinate multidisciplinary care with pediatric colorectal surgery, pelvic‑floor physical therapy, and behavioral specialists for optimal outcomes.