Presenting Complaint:

• Diarrhoea

Symptoms:

• Onset: Gradual, worsening over past 6 months – “Today I’ve been every couple hours”
• Character: Loose, watery, sometimes bulky stools – “I feel it’s very liquidy”
• Associated symptoms: Bloating, fatigue, mild lower abdominal cramping, occasional mouth ulcers – “My tummy hurts sometimes. I keep randomly having ulcers on my mouth”
• Exacerbating/alleviating factors: Worse after bread, pasta and pizza – “After I eat carbs, I always get diarrhoea”
• Severity: Severe – “I had to go to the bathroom so much I couldn’t go to work today”

Systemic Symptoms (answer only if specifically asked for):

• Urinary: Normal urinary colour and frequency, no obvious blood
• Bowels: 12x bowel movements today, greasy, pale stools, no blood or mucus noted, mild bloating
• Fever: None
• Weight loss: Unintentional weight loss (~4kg over 3 months)
• Night sweats: None
• Vomiting and nausea: No vomiting, intermittent nausea
• Pruritus: Intermittent itchy rash on elbows and knees (noted recently)
• Reflux: None
• Fatigue: Persistent tiredness, difficulty concentrating
• Menses: Regular menses, no menorrhagia or dysmenorrhoea

Past Medical History:

• No known chronic illness
• Iron deficiency anaemia treated with oral iron tablets

Past Surgical History:

• None

Drug History:

• Ferrous sulfate (irregular adherence)
• Contraceptive pill

Allergies:

• NKDA

Family History:

• Mother has hypothyroidism (Hashimoto’s)
• Maternal aunt has irritable bowel syndrome
• No family history of IBD, bowel cancer or other autoimmune disease

Social History:

• BMI 21
• Non-smoker
• Alcohol: Occasionally drinks alcohol socially, beer causes onset of diarrhoea
• Occupation: Primary school teacher
• Diet: Varied, high in bread or pasta
• Lives with partner, no children

Ideas, Concerns, and Expectations:

• Think it could be IBS like her aunt
• Worried it could be a serious bowel problem
• Wants to stop feeling tired and missing work

Observations:

• Respiratory rate: 16
• Oxygen sats: 98% on room air
• Pulse: 92
• Blood pressure: 110/70
• Alert
• Temperature: 37.2

NEWS: 2 

Examination:

General Inspection:

• Appears tired
• Slim body habitus
• Conjunctival pallor
• No jaundice or peripheral oedema 

Hands:

• No clubbing or tremor
• Mild pallor, brittle nails
• Capillary refill time < 2 seconds
• Peripheries cool
• Regular pulse and rhythm 
• No palmar erythema or Dupuytren’s contracture
• Rash apparent on elbows (see below):

Image sourced from DermNetNZ: https://dermnetnz.org/topics/dermatitis-herpetiformis. Used in accordance with image licensing policy CC BY-NC-ND 4.0. 

Face:

• No scleral icterus present
• Aphthous ulcers on buccal mucosa
• Slightly dry mucous membranes 

Ulcers of oral mucosa. Author: Florian Brandt. Sourced from Wikimedia Commons in accordance with licensing policy.

Neck:

• JVP not raised
• No thyroid enlargement
• No scars or palpable lymphadenopathy

Chest:

• No spider naevi 

Abdomen:

Inspection

• Slightly distended
• No scars visible

Palpation

• Abdomen soft and mildly tender on palpation of lower abdomen without guarding
• No hepatomegaly or splenomegaly palpable
• No palpable renal or aortic/pulsatile masses
• No suprapubic tenderness or distension

Percussion

• Tympanic, rumbling sounds on percussion

Auscultation

• Bowel sounds present and slightly increased
• No bruits heard

Special tests:

• Fluid thrill -> negative
• If performed or asked for – DRE, examination of external hernial orifices and external genitalia are normal

Other:

• No peripheral or sacral oedema

Laboratory tests:

• Hb 9.8 g/dL (Normal Hb range: 11.5–15.5 g/dL)
• MCV 72 fL (Normal MCV range: 80-100 fL)
• Ferritin 8 µg/L (Normal ferritin range: 15-200 µg/L)
• CRP 10 mg/L (Normal CRP range: < 5 mg/L)
• Urea 14.5 mmol/L (Normal urea range: 2.5-7.0 mmol/L)
• Creatinine 145 µmol/L (Normal creatinine range: 45-90 µmol/L)
• eGFR 48 mL/min/1.73 m² (Normal eGFR range: > 90 mL/min/1.73 m²)
• Sodium 148 mmol/L (Normal sodium range: 135-145 mmol/L)
• Potassium 4.9 mmol/L (Normal potassium range: 3.5-5.0 mmol/L)

Examiner questions:

1. What is your main differential diagnosis and why is this more likely than other differentials?

Main differential: Undiagnosed Coeliac Disease – acute flare with diarrhoea and evidence of AKI.

• Recurrent diarrhoea, unintentional weight loss, steatorrhea, and features of malabsorption (iron deficiency anaemia and mouth ulcers) are suggestive of coeliac disease.
• History suggests the likely cause of diarrhoea episodes is gluten-containing foods (bread, pasta, pizza), which are one of the most common triggers of coeliac disease.
• Diagnosis of coeliac disease is confirmed by serology, endoscopy and biopsy, as well as exclusion of other causes of diarrhoea, with iron deficiency anaemia being unexplained by dietary intake alone.

Other differentials:

• Irritable bowel syndrome (IBS) is common in young women and can cause diarrhoea, but IBS does not typically cause weight loss, anaemia, or abnormal blood results.
• Inflammatory bowel disease can cause diarrhoea and weight loss, but usually associated with raised inflammatory markers, rectal bleeding, or abdominal pain. There is a typical relationship in the history with gluten-containing foods. Faecal calprotectin can be used to rule out.
• Infectious diarrhoea remains a possibility, however is less likely as symptoms are chronic rather than acute, and in this case there is a characteristic relationship with gluten-containing food. Would perform stool MC&S to rule out infectious causes.
• Hyperthyroidism is a cause of diarrhoea and weight loss, which can also be associated with autoimmune disease (e.g. Graves’), however often presents with other symptoms of hyperthyroidism such as thyroid eye disease, heat intolerance, light menses, anxiety, tachycardia and palpitations, tremor. Can be ruled out by measuring TFTs.
• Less likely to be lactose intolerance due to the presence of iron deficiency and mouth ulcers.
• Less likely to be microscopic colitis, as it usually presents in older adults as watery diarrhoea without signs of malabsorption or anaemia.

2. Describe the investigation and management of this condition while the patient is admitted 

Possible answer: 

• A-E assessment and regular monitoring. Strict fluid balance and urine output monitoring. Obtain IV access and repeat bloods. 
• Fluid resuscitation for AKI and dehydration: IV crystalloids to correct dehydration and restore renal perfusion. Stop nephrotoxic medications. Escalate to renal team if creatinine continues to rise despite fluids. Daily monitoring of renal function until recovers to baseline.
• Serological testing: tissue transglutaminase IgA antibodies (tTG-IgA) alongside total IgA (to exclude IgA deficiency).
• Endoscopy with duodenal biopsy: to confirm diagnosis and look for villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis.
• Blood tests to identify micronutrient deficiencies (iron studies, B12, folate, vitamin D, calcium, magnesium, albumin).
• Other tests to rule out other differentials (FBC, CRP, stool MC&S and calprotectin, thyroid function tests).

3. How is coeliac disease managed?

Possible answer: 

• Lifelong strict gluten-free diet – avoidance of all wheat, rye, and barley. Oats may be tolerated if certified gluten-free.
• Dietitian input – education on hidden sources of gluten and ensuring nutritional adequacy.
• Monitor nutritional deficiencies – check and correct iron, folate, vitamin B12, vitamin D, calcium. Vitamin D and calcium supplements commonly provided.
• Bone health monitoring – DEXA scan if at risk of osteoporosis due to chronic malabsorption.
• Vaccinations – pneumococcal and annual influenza vaccine due to increased infection risk from the functional hyposplenism that is seen in coeliac disease.
• Follow-up serology – monitor adherence to the gluten-free diet by checking for antibody resolution.

4. Name some possible complications of coeliac disease

Local complications:

• Malabsorption and micronutrient deficiency
• Osteoporosis or osteopenia
• Infertility 
• Dermatitis herpetiformis

Systemic complications:

• Hyposplenism
• Malignancy risk (small bowel adenocarcinoma and enteropathy-associated T cell lymphoma)
• Other autoimmune diseases (T1DM, autoimmune thyroid disease)