Chronic diarrhoea

Question 1

Red flags on history?

Answer 1

PR bleeding, systemically unwell, unintentional weight loss, family history bowel/ovarian cancer, nocturnal, new onset (<3 months)

Question 2

Initial investigations?

Answer 2

FBC, EUC, LFT, CRP, ferritin, TSH, coeliac serology, (vit B12/vit D), stool m/c/s and o/c/p x 3; C diff toxin / PCR, FCT, FIT*

Question 3

When do you not use FCP?

Answer 3

Acute severe symptoms suggestive of IBD; if malignancy suspected; generally not over 50 but could extend to 60 if risk of malignancy very low; FIT+

Question 4

When do you use FIT? NB Single stool sample

Answer 4

As a rule out test in low risk groups for malignancy if PR bleeding is not present but still have unexplained symptoms not fulfilling criteria for 2 week referral pathway (although still needs careful monitoring as 3% of bowel cancer cases in these) - specialists don’t agree with NICE guidelines re this
e.g. age >40 with abdo pain OR weight loss
age <60 with IDA or CIBH
age>60 with iron deficiency without anaemia

Question 5

What are two other causes of chronic diarrhoea that you have learnt about?

Answer 5

1. Immunosuppression - HIV (test for cryptosporidium and norovirus)
2. Ovarian cancer - test for Ca-125 if over 50

Question 6

In patients with signs/symptoms suggestive of functional bowel disorder, normal FCP and investigations who have atypical, persistent or severe symptoms, referral to secondary care is still warranted. What are some of the other causes they will exclude?

Answer 6

Malignancy, bile salt malabsorption, chronic pancreatitis, microscopic colitis (esp if diarrhoea only rather than diarrhoea + constipation) NB Calprotectin does not pick up microscopic colitis

Question 7

What other test do you need to consider when ordering a stool m/c/s and o/c/p?

Answer 7

C. diff toxin and PCR

Question 8

What are some causes of faecal incontinence?

Answer 8

Perianal fistula, impaction with overflow, pelvic floor dysfunction e.g. postnatal

Question 9

What are the NICE guidelines for CRC 2 week pathway referral?

Answer 9

• Age >40 with abdominal pain and weight loss
• Age >50 with PR bleeding
  (if <50 consider if also has abdo pain, weight loss, change in bowel habit, IDA)
• Age >60 with IDA or change in bowel habit
  Consider if rectal or abdominal mass

Question 10

How many % of bowel cancer cases occur in patients <40 and how many between 40 and 50?

Answer 10

1% and 9% i.e. 90% over age 50

Question 11

What are the differentials for chronic diarrhoea?

Answer 11

1. IBS including SIBO or FODMAP/lactose malabsorption; IBD; malignancy; coeliac disease
2. Hyperthyroidism
3. Infection
4. Pancreatic insufficiency, bile salt malabsorption
5. Rarities - ovarian cancer, immunosuppression

Question 12

What is the sensitivity and specificity of FCP?

Answer 12

<50: sensitivity 88%; specificity 78%; <100: sensitivity 96%, specificity 76%