IBD History Taking OSCE — Crohn's vs UC, Extraintestinal Features, Management

Why IBD History Is Tested

Inflammatory bowel disease affects approximately 500,000 people in the UK and is a common presentation in medicine, surgery, and gastroenterology OSCEs. Examiners test this station because it requires distinguishing two important conditions (Crohn's disease and ulcerative colitis), eliciting extraintestinal manifestations, and demonstrating patient-centred communication around a chronic condition with significant quality-of-life impact.

Opening the Consultation

Introduce yourself, confirm identity, explain the purpose of the consultation, and check the patient is comfortable. Use open questions first: "Could you tell me what's been happening with your bowels?" Allow the patient to describe their experience before directing the history.

Presenting Complaint and History of Presenting Complaint

Bowel Symptoms

Characterise the stool systematically:

• Frequency — number of stools per day and night (Bristol Stool Chart type)
• Consistency — formed, loose, watery, or liquid
• Blood — fresh red blood (UC), mixed through stool, on paper only
• Mucus — clear or bloody mucus discharge
• Urgency — how much warning before needing to defecate
• Tenesmus — sensation of incomplete evacuation (suggests rectal involvement)
• Nocturnal symptoms — waking to defecate (suggests significant inflammation)
• Incontinence — highly impactful, always ask sensitively

Pain

• Site: periumbilical/right iliac fossa (Crohn's), left iliac fossa/generalised (UC)
• Character: crampy, colicky, constant
• Relation to defecation: relieved by opening bowels (colitis) vs not relieved (Crohn's with obstruction)

Constitutional Symptoms

• Fever, night sweats, weight loss
• Fatigue (anaemia, active inflammation)
• Anorexia

Crohn's Disease vs Ulcerative Colitis: Key Distinguishing Features

Extraintestinal Manifestations

Always ask specifically about extraintestinal features — they are commonly tested in OSCEs:

Perianal and Fistula History (Crohn's)

Ask about:

• Perianal pain, swelling, or discharge (abscess, fistula)
• Skin tags around the anus
• Fistulae: entero-enteric, enterocutaneous, rectovaginal (women — faecal per vaginum)
• Previous perianal surgery or drainage

Past Medical and Surgical History

• Previous IBD diagnoses and when established
• Previous flares — how many, how severe, requiring hospital admission
• Previous surgery: bowel resection (note which segment — affects investigations and malabsorption), stoma formation, perianal procedures
• Colonoscopy and biopsy results
• Other autoimmune conditions: primary sclerosing cholangitis, autoimmune hepatitis, psoriasis, ankylosing spondylitis

Medications

Take a detailed drug history — this is commonly tested:

Ask about:

• Current medications and doses
• Previous medications and why stopped (side effects, failure, remission)
• Steroid courses — frequency and duration (adrenal suppression risk)
• NSAID use — can precipitate IBD flares
• Antibiotics — Clostridioides difficile superinfection

Family History

Enquire about IBD in first-degree relatives (10-fold increased risk), colorectal cancer, and PSC.

Social History

• Smoking: Crohn's worsened by smoking; UC improved by smoking (cessation can precipitate flare)
• Alcohol: can worsen inflammation, interacts with methotrexate
• Occupation: impact on work, time off, access to toilets
• Diet: exclusion diets, nutritional deficiencies (B12 in terminal ileal Crohn's, iron in blood loss UC)
• Travel history: exclude infectious diarrhoea

Quality of Life and ICE

Always explore impact:

• Work and daily activities
• Social life and relationships
• Emotional wellbeing (anxiety and depression are common)
• Bathroom access and urgency affecting going out
• Sexual health (perianal disease, body image, stoma)

Use ICE: Ideas (what does the patient think is happening), Concerns (biggest worry — cancer? surgery? dependency on steroids?), Expectations (what do they want from today).

Mark-Scheme Checklist

Common Mistakes

Frequently Asked Questions

"How do I differentiate Crohn's disease from ulcerative colitis in an OSCE history?"

The key distinguishing features can be systematically elicited from the history. UC characteristically presents with bloody diarrhoea with mucus, rectal urgency and tenesmus, and symptoms that are worse distally — reflecting continuous mucosal inflammation from the rectum proximally. Crohn's disease can affect anywhere from mouth to anus with skip lesions and often presents with abdominal pain, weight loss, and a palpable right iliac fossa mass if the terminal ileum is involved. Perianal disease (fistulae, skin tags, abscesses) is strongly associated with Crohn's. Smoking worsens Crohn's but paradoxically reduces risk of UC. Obstructive symptoms suggest Crohn's strictures. Asking about previous endoscopy and biopsy results is valuable — histological features (transmural inflammation, granulomas in Crohn's; crypt abscesses, continuous mucosal inflammation in UC) are diagnostic. In the OSCE, present your differential with the distinguishing features you have elicited.

"What extraintestinal manifestations of IBD should I always ask about?"

Extraintestinal manifestations (EIMs) affect up to 40% of IBD patients and are commonly tested. They divide into those that parallel disease activity and those that run an independent course. Parallel EIMs include peripheral arthropathy (large joint, asymmetric, non-erosive), erythema nodosum (painful red nodules on shins), and episcleritis. Independent EIMs include sacroiliitis and ankylosing spondylitis, pyoderma gangrenosum (deep ulcerating skin lesion), uveitis (anterior, painful red eye with visual change), and primary sclerosing cholangitis (PSC — biliary stricturing, strongly associated with UC, check LFTs and ALP). PSC is particularly important because it carries an independent risk of cholangiocarcinoma and requires surveillance colonoscopy even in remission. Always ask about joint symptoms, eye redness or pain, and skin lesions when taking an IBD history.

"What medications are used in IBD and what monitoring is required?"

IBD management follows a step-up approach. Aminosalicylates (mesalazine, sulfasalazine) are first-line for mild-moderate UC and require annual renal function monitoring due to nephrotoxicity risk. Corticosteroids (prednisolone, budesonide) induce remission in flares but are not used for maintenance — patients on frequent courses need bone protection (vitamin D, calcium, bisphosphonate) and adrenal function consideration. Thiopurines (azathioprine, mercaptopurine) are maintenance immunosuppressants — TPMT enzyme level must be checked before starting as deficiency causes severe myelosuppression; FBC and LFTs require monitoring every 3 months. Biologics (infliximab, adalimumab, vedolizumab, ustekinumab) are used in moderate-severe disease — TB screening (IGRA/chest X-ray), hepatitis B serology, and VZV status must be checked before initiation. Methotrexate is used in Crohn's, requiring strict contraception and liver monitoring.

"How do I assess the severity of an IBD flare in a history?"

The Truelove and Witts criteria are used for UC severity. Mild: less than 4 stools/day, no systemic upset. Moderate: 4-6 stools/day, minimal systemic features. Severe: more than 6 bloody stools/day plus any of: temperature over 37.8°C, heart rate over 90 bpm, haemoglobin under 105 g/L, ESR over 30. Severe UC flare requires hospital admission, IV hydrocortisone, and consideration of rescue therapy (ciclosporin, infliximab) or emergency colectomy. For Crohn's, the Harvey-Bradshaw Index or HBI is used clinically. In the OSCE history, assess severity by asking about stool frequency, blood, systemic features (fever, sweats, weight loss), functional impact, and previous hospitalisations. Ask specifically about symptoms of toxic megacolon: abdominal distension, reduced bowel sounds, fever, tachycardia — this is a surgical emergency.

"What surgical history is important to take in IBD?"

Surgery is more common in Crohn's disease (around 50% require surgery within 10 years) but colectomy is curative in UC. Take a detailed surgical history: type of operation (right hemicolectomy, ileocaecal resection, segmental resection in Crohn's; subtotal colectomy, panproctocolectomy, ileal pouch-anal anastomosis (IPAA/J-pouch) in UC), when performed, reason (failed medical therapy, complication, dysplasia, emergency), and outcome. For Crohn's, note how much bowel remains — extensive resection raises the risk of short bowel syndrome and nutritional deficiency. Ask about stoma formation: ileostomy or colostomy, temporary or permanent, and its impact on daily life. After J-pouch formation in UC, ask about pouchitis symptoms (increased frequency, urgency, bleeding) as this occurs in up to 50%. Previous surgery modifies future options and investigations.

"How does IBD affect quality of life and what should I explore?"

IBD has profound quality-of-life effects that are highly relevant to both the history and the OSCE mark scheme. The unpredictability of urgency and accidents drives significant anxiety — patients may plan their lives around toilet access and avoid social situations, travel, or exercise. Depression affects around 25% of patients with active IBD and should be screened for. Fatigue is one of the most prevalent and disabling symptoms, often present even in remission, and is multifactorial (anaemia, poor sleep, psychological impact, disease activity). Body image is affected by weight loss, skin manifestations, perianal disease, and stoma. Sexual function may be impaired by perianal disease, rectovaginal fistulae, or body image concerns. Occupational impact is significant — absenteeism and presenteeism are common. In the OSCE, always ask "How has this affected your day-to-day life?" and follow up on work, relationships, and emotional wellbeing.

Related guides: Abdominal Examination OSCE · Lower GI Bleeding OSCE · Jaundice History OSCE · Ascites Examination OSCE · How to Take an Abdominal History OSCE