The American Board of Colon and Rectal Surgery certifies in two stages: a written Part 1 covering the full spectrum of coloproctology and its underlying basic science, and a Part 2 oral examination in which at least three thirty-minute sessions probe clinical judgement in front of two examiners each. Practise with colorectal clinical vignettes referenced to ASCRS and NCCN guidelines, and rehearse the oral component in the Exam Simulator.
Content reviewed 26 August 2026 against current guidelines.
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A 39-year-old male manual worker presents with a painful discharging sinus in the natal cleft. He has had two previous incision and drainage procedures for pilonidal abscess under local anaesthesia over the past 18 months. On examination, there is a pit at the natal cleft midline with a lateral sinus track 3 cm to the left of the midline, and surrounding erythema and chronic granulation tissue. He is keen for a definitive procedure and asks about his options. His BMI is 27 kg/m² and there are no significant comorbidities. Which surgical procedure is most appropriate for definitive treatment of his chronic pilonidal sinus disease?
Correct answer: C
✓ Correct answer: Chronic and recurrent pilonidal sinus disease is best managed with off-midline flap techniques. Both the Karydakis flap and the Bascom cleft-lift procedure achieve wound closure away from the midline natal cleft, thereby eliminating the anatomical factors (deep natal cleft, hair follicle traction) that predispose to pilonidal disease recurrence. Multiple RCTs and systematic reviews demonstrate that off-midline closure techniques (Karydakis, Bascom, Limberg) have significantly lower recurrence rates (approximately 2–10%) compared to primary midline closure (recurrence 15–25%) and healing by secondary intention (very low recurrence but prolonged healing time and poor time-off-work outcomes). ESCP 2019 guidelines and the British Society of Coloproctology recommend off-midline closure as the preferred technique for primary and recurrent pilonidal disease requiring surgery. The Karydakis flap involves excision of the sinus with an eccentric ellipse and advancement of the medial flap, displacing the wound off the midline. Bascom's cleft-lift (cleft closure) obliterates the deep natal cleft. Both are suitable for this patient who is a manual worker prioritising low recurrence. ✗ Why the others are wrong: A: Wide local excision with secondary intention healing has low recurrence but is associated with prolonged healing (8–16 weeks), significant time off work, and substantial nursing input. It is not the gold standard for a manual worker seeking definitive treatment. B: Primary midline closure is associated with recurrence rates of 15–25% due to wound tension, poor tissue perfusion at the midline, and persistence of the causal anatomical factors. It is inferior to off-midline techniques. D: The Limberg rhomboid transposition flap is also an off-midline technique with excellent recurrence rates and is a valid option. However, it is not exclusively 'reserved for recurrent disease after previous flap failure' — this is an artificial restriction. C is the best answer as it names both Karydakis and Bascom as the standard first-line off-midline options. E: EPSiT is a minimally invasive option with growing evidence (particularly in Italian literature), but it is not universally endorsed as first-line treatment in current ESCP/BSCP guidelines and is better suited to simple primary disease without complex chronic tracks. Teaching point: Off-midline closure (Karydakis flap, Bascom cleft-lift) is the surgical standard for chronic/recurrent pilonidal sinus disease. Midline closure has unacceptably high recurrence rates. Secondary intention healing is suitable for simple acute cases but impractical for manual workers. Board pearl: Off-midline techniques → recurrence 2–10%. Midline closure → recurrence 15–25%. Always prefer Karydakis or Bascom for recurrent pilonidal disease in fit patients. The Limberg flap is an equally valid off-midline option. Pitfall: Primary midline closure is NOT the preferred technique despite being the most technically straightforward — it should not be chosen when an off-midline flap is feasible.
Teaching point. Off-midline closure (Karydakis flap, Bascom cleft-lift) is the surgical standard for chronic/recurrent pilonidal sinus disease. Midline closure has unacceptably high recurrence rates. Secondary intention healing is suitable for simple acute cases but impractical for manual workers.
Referenced to ESCP Pilonidal Sinus Guidelines 2019; BSCP Guidelines 2019
Every question is explained like this — start with 50 free ›Every question is written by Pablo Lozano Lominchar, MD, PhD, and mapped to this board’s published syllabus. Before it enters the bank it has to pass an automated check: five options, a written explanation, and a citation — a named society guideline or a named trial. Benign and functional topics cannot be published without a society guideline; oncological ones cite NCCN, ESMO or AJCC, and the classification systems that govern a topic — Bethesda, TIRADS, Atlanta, Prague, Chicago — have to appear where they apply. The author has audited the full active bank against current guideline versions: what fails is re-cited, rewritten or withdrawn. 650 questions are currently withdrawn and are served to nobody.
Scope of authorship. ABCRS sits outside the author’s own subspecialty practice, which is surgical oncology — peritoneal malignancy, sarcoma, hepatopancreatobiliary and complex pelvic surgery. No diplomate of this board has signed these questions off. What they offer is traceability rather than personal authority: every answer names the current guideline or trial it rests on, so you can check it at the source before you trust it. Found an error? Tell us — it gets corrected or withdrawn.
It has two parts. Part 1 is a written multiple-choice examination of about six hours at a Pearson VUE centre, covering the spectrum of colon and rectal surgery together with the relevant basic science, radiology and pathology. Part 2 is an oral examination consisting of at least three thirty-minute sessions, each conducted by a team of two examiners, assessing clinical experience, problem-solving and surgical judgement.
You must have passed the American Board of Surgery qualifying examination before being admitted to ABCRS Part 1, and hold full American Board of Surgery certification before being admitted to Part 2. Completion of an ACGME-accredited colon and rectal surgery fellowship is required, along with a current, valid, full and unrestricted licence to practise maintained throughout the process.
The oral tests judgement rather than recall, so rehearsal matters more than volume. Work through colorectal cases out loud until you can state the staging, the multidisciplinary decision, the operative plan and the supporting evidence without hesitating. The SurgBoardsQ&A Exam Simulator runs this format: it presents a case step by step and follows up whenever your reasoning is incomplete.
SurgBoardsQ&A provides 1,168 colorectal and peritoneal practice questions mapped to the coloproctology syllabus, each with a full explanation referenced to the ASCRS clinical practice guidelines or the relevant NCCN guideline.
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