Synopsis
Recognise perianal sepsis promptly, map fistula anatomy and rectal inflammation, and combine drainage, continence-preserving surgery and effective Crohn therapy through a specialist multidisciplinary service.
- Perianal Crohn disease includes abscess, fistula, ulceration, fissure, skin tags, stenosis and rectovaginal or anovaginal disease; it may precede recognised luminal inflammation.
- Pain, fever or swelling is an abscess until assessed; urgent examination and drainage take priority over escalating biologic treatment or waiting for elective MRI.
- Pelvic MRI and examination under anaesthesia are complementary: MRI maps tracts and occult collections, while EUA confirms openings and permits drainage or seton placement.
Key red flags
Perianal pain with fever, spreading cellulitis, urinary retention, immunosuppression or sepsis requires urgent colorectal assessment and drainage; antibiotics alone are insufficient source control.
Investigation priorities
Map primary tract, sphincter relation, secondary branches, horseshoe extension and abscess.
Management branches
Pain, swelling, fever, systemic upset or imaging suggests a perianal abscess.
- Assess ABCDE, analgesia, antibiotics for systemic infection and urgent colorectal review, recognising that deep sepsis can lack a visible fluctuant lump.
- Proceed to timely examination under anaesthesia and incision or internal drainage; obtain MRI first only when stable and it will not postpone source control.
Key medicines
InfliximabWeight-based induction and maintenance through a specialist fistulising Crohn protocol.
Antibiotic adjunctShort culture- and local-protocol-guided course for cellulitis, sepsis or postoperative drainage.