Inflammatory Bowel Disease — Viva

Long Case Viva Defence

Candidate's opening statement (model answer)

"Mr James O'Brien is a 42-year-old mechanical engineer who presents with a 4-day history of worsening bloody diarrhoea (12 stools per day), abdominal cramping and fever. He has a 10-year history of extensive ulcerative colitis managed with mesalazine 2 g daily and azathioprine 150 mg daily. He also has primary sclerosing cholangitis diagnosed 3 years ago, with stable cholestatic liver function tests. [1]

On examination he is febrile at 38.3, tachycardic at 104, with left iliac fossa tenderness but no signs of peritonism. [1]

His main problems are:

1. Acute severe ulcerative colitis — Truelove-Witts severe (more than 6 bloody stools, tachycardia, fever, Hb 99)
2. Primary sclerosing cholangitis — increasing his colorectal cancer surveillance burden
3. Steroid-refractory risk — he is already on azathioprine 2 mg/kg, suggesting immunomodulator-refractory disease
4. Colitis-associated neoplasia risk — 10 years pancolitis plus PSC mandates annual chromoendoscopy surveillance
5. VTE risk — acute severe colitis is a prothrombotic state
6. Anaemia of chronic disease [1]

My immediate management priorities are admission for IV hydrocortisone, stool studies to exclude C. difficile and CMV, flexible sigmoidoscopy to assess severity, and day-3 assessment with Oxford criteria. If steroid-refractory, I will proceed to infliximab rescue. Given his PSC, his colorectal cancer surveillance is annual chromoendoscopy, which I will schedule once this flare has resolved." [1]

Examiner probing questions and model answers

Q1: "It is day 3. His stool frequency is still 9 per day and his CRP is 52. What do you do?" [1]

"This meets the Oxford criteria for predicted colectomy — stool frequency more than 8 per day on day 3 predicts colectomy in approximately 85 per cent of patients. He is steroid-refractory. I would proceed to rescue therapy with infliximab 5 mg/kg as a single dose. The Järnerot study demonstrated that infliximab reduced the 3-month colectomy rate compared to placebo in steroid-refractory acute severe UC. If infliximab were contraindicated or unavailable, ciclosporin 2 mg/kg/day IV is an equally effective alternative — the CYSIF trial and the CONSTRUCT trial both demonstrated equipoise between infliximab and ciclosporin for short-term outcomes. My choice of infliximab is based on its simpler administration and the fact that if it works, I can continue it as maintenance therapy, whereas ciclosporin is only a bridge to another oral maintenance agent." [1]

Q2: "Why does he need annual surveillance rather than the standard 1- to 2-yearly?" [1]

"He has two independent risk factors for colitis-associated neoplasia: 10 years of extensive colitis, which puts him in the standard surveillance group, and primary sclerosing cholangitis. PSC markedly increases colorectal cancer risk — 3- to 5-fold above UC alone — and this risk is independent of colitis activity. For this reason, surveillance begins at the time of PSC diagnosis regardless of colitis duration and is performed annually. The recommended technique is dye-spray chromoendoscopy with targeted biopsies, which increases dysplasia detection 2- to 3-fold compared to white-light colonoscopy with random biopsies. His PSC-UC phenotype also typically shows rectal sparing and backwash ileitis." [1]

Q3: "He responds to infliximab. How do you plan his maintenance therapy?" [1]

"Given that he has proven steroid-refractory, immunomodulator-refractory disease, his maintenance needs to be escalated beyond his current azathioprine. I would continue infliximab 5 mg/kg every 8 weeks as maintenance, in combination with his azathioprine — this combination reduces immunogenicity and improves drug levels compared to infliximab monotherapy. If he develops anti-drug antibodies or loses response, I would switch to vedolizumab (gut-selective anti-integrin, 300 mg IV at weeks 0, 2, 6, then every 8 weeks) or tofacitinib (oral JAK inhibitor). However, I would be cautious with tofacitinib given his age and the post-marketing safety signal for cardiovascular events and malignancy in older patients with cardiovascular risk factors from the ORAL Surveillance study. The target is endoscopic healing — Mayo endoscopic subscore 0 to 1 — assessed by colonoscopy at 6 to 9 months, consistent with the STRIDE-II treat-to-target framework." [1]

Q4: "What is the significance of his PSC for his overall prognosis?" [1]

"PSC is a chronic cholestatic disease with no proven medical therapy that halts progression. It carries a significantly increased risk of cholangiocarcinoma (lifetime risk 10 to 15 per cent), gallbladder cancer, and colorectal cancer (in the setting of associated colitis). Median survival from diagnosis to death or transplant is about 10 to 12 years without transplant. His management should include annual colorectal surveillance, cholangiocarcinoma surveillance (annual MRCP and CA 19-9, though this is debated), and early liver transplant referral if he develops decompensation, dominant strictures requiring endoscopic dilatation, or cholangiocarcinoma. His IBD management is otherwise standard, though the PSC-UC phenotype often has milder colitis than non-PSC UC." [1]

Q5: "How would his management change if he had Crohn's disease instead of UC?" [1]

"The key differences would be: first, colectomy would not be curative — Crohn's recurs at the anastomosis in the majority of patients, so surgery is a last resort rather than a definitive therapy. Second, the phenotype would determine management — if he had stricturing disease (B2), I would be cautious with steroids because they worsen fibrotic strictures without relieving the mechanical obstruction. If he had fistulising disease (B3), I would need to exclude abscess before starting anti-TNF, using EUA and pelvic MRI. Third, the combination therapy evidence is different — the SONIC trial specifically demonstrated combination infliximab plus azathioprine superiority in immunomodulator-naive Crohn's. Fourth, small bowel assessment with MRE would be essential because colonoscopy only reaches the terminal ileum. Finally, ustekinumab and vedolizumab have different evidence profiles in Crohn's versus UC." [1]

Q6: "He asks about the safety of infliximab. What do you tell him?" [1]

"Before starting infliximab, I would screen for latent tuberculosis (quantiferon-Gold and chest X-ray), hepatitis B and C, and HIV, because anti-TNF can reactivate these infections. The main risks are: serious infection (approximately 2 per cent per year), reactivation of latent TB or HBV, infusion reactions (reduced by premedication and combining with an immunomodulator), drug-induced lupus, and a small theoretical risk of lymphoma (particularly hepatosplenic T-cell lymphoma in young males on combination anti-TNF plus thiopurine — though this is very rare). The benefits — avoidance of colectomy, mucosal healing, restoration of quality of life — substantially outweigh these risks in a patient with severe steroid-refractory disease. I would document this discussion and proceed once he consents." [1]

Short Case Discussion

Scenario: "Examine this patient's abdominal system and describe any extraintestinal manifestations"

Candidate presentation (model): [1]

"I examined Mrs Patel's abdominal system. She is comfortable at rest but has a moon face and central obesity consistent with corticosteroid use. On general inspection, there are tender erythematous nodules on the anterior aspects of both shins, consistent with erythema nodosum. There is an aphthous ulcer on the buccal mucosa. [1]

On the hands, there is no clubbing, palmar erythema or Dupuytren contracture. There is no peripheral arthritis today. The eyes show no episcleritis or uveitis. There is no icterus. [1]

On examination of the abdomen, there is a right iliac fossa scar consistent with a previous ileocaecal resection. The abdomen is soft with mild right iliac fossa tenderness. There is no palpable mass, hepatosplenomegaly or ascites. Bowel sounds are normal. On perianal examination, there are two skin tags but no fissure, fistula or abscess. [1]

In summary, these findings are consistent with Crohn's disease with an activity-related extraintestinal manifestation (erythema nodosum and aphthous stomatitis). The right iliac fossa scar suggests previous ileocaecal resection. I would like to take a full surgical and medication history, check inflammatory markers and faecal calprotectin, and organise an MR enterography to assess for disease recurrence." [1]

Examiner: "Are the erythema nodosum and the bowel disease linked?" [1]

"Yes. Erythema nodosum is an activity-related extraintestinal manifestation of IBD — it tracks the bowel inflammation and typically resolves with treatment of the underlying colitis or Crohn's flare. This contrasts with activity-independent manifestations such as axial spondyloarthritis, primary sclerosing cholangitis, uveitis and pyoderma gangrenosum, which run their own course independent of bowel activity and require separate management. The distinction matters because treating the gut will improve erythema nodosum but will not necessarily improve an activity-independent manifestation like ankylosing spondylitis." [1]

Examiner: "What is the significance of the right iliac fossa scar?" [1]

"This is consistent with a previous ileocaecal resection — the most common surgical procedure for Crohn's disease. Post-operative recurrence of Crohn's at the anastomosis is very common — up to 70 to 80 per cent endoscopically at 1 year without preventive therapy. Patients at high risk of recurrence — those with penetrating disease behaviour, prior resections, or short bowel risk — should start anti-TNF or immunomodulator early after surgery to prevent recurrence. I would assess her current disease activity with faecal calprotectin and an MR enterography, and perform an ileocolonoscopy to assess for post-operative recurrence at the anastomosis using the Rutgeerts score." [1]

Examiner: "How would you classify the extraintestinal manifestations you found?" [1]

"Erythema nodosum and aphthous stomatitis are both activity-related manifestations — they parallel gut inflammation and typically improve with treatment of the underlying bowel disease. I would also screen for other activity-related manifestations: Type 1 peripheral arthritis (asymmetric oligoarticular, large joints) and episcleritis. For activity-independent manifestations, I would ask about inflammatory back pain (suggesting axial spondyloarthritis), screen for PSC with liver function tests, and examine the eyes for uveitis. Pyoderma gangrenosum is another activity-independent manifestation that typically presents as a painful ulcer with undermined edges on the legs." [1]