InvestigationsPotential resultsClinical management plan: abnormal results
Dietary/ lifestyle/ medications assessmentHigh dietary fat intake
Low/high fibre intake
High fizzy drink intake
High use of sorbitol-containing chewing gum or sweets
High caffeine intake
High alcohol intake
Drug induced, eg,
  • PPIs

  • Laxatives

  • β blockers

  • Metformin

  1. Dietary advice about healthy fibre and dietary fat intake.

  2. Referral to dietitian and ask patient to complete 7-day dietary diary beforehand.

  3. Lifestyle advice about smoking cessation.

  4. Consider referral for psychological support.

  5. Medications advice.

  6. Antidiarrhoeal ± bulk laxative.

Routine AND additional blood screen (pages 2–3)Abnormal results
Mg2+ low
Coeliac disease
Follow treatment of abnormal blood results (pages 2–3).
  1. If IgA deficient, request IgG coeliac screen.

  2. Confirm with duodenal biopsy.

  3. Refer to dietitian for gluten free diet.

  4. Liaise with GP regarding long term monitoring of bone densitometry and referral to a coeliac clinic.

Stool sample: for microscopy, culture and Clostridium difficile toxinStool contains pathogenTreat as recommended by the microbiologist and local protocols.
Stool sample: for faecal elastaseEPISee EPI (page 16)
OGD with duodenal aspirate and biopsies and/or glucose hydrogen (methane) breath testSIBOTreatment for SIBO (page 17).
Carbohydrate challengeSpecific disaccharide intoleranceAppropriate treatment (pages 16–17).
SeHCAT scanBAMTreatment for BAM (page 16).
Abdominal X-rayFaecal loading with overflowBulking agent.
1st Line
Flexible sigmoidoscopy with biopsies from non-irradiated bowel (avoid biopsies from areas obviously irradiated in sigmoid and rectum)Radiation proctopathy and frequency of defecation
  1. Pelvic floor and toileting exercises (page 18)—min. 6 weeks.

  2. Add stool bulking agent to pelvic floor exercise regimen.

  3. Antidiarrhoeal ± stool bulking agent.

Radiation proctopathy/colopathy and pelvic floor dysfunction (page 17)
  1. Antidiarrhoeal.

  2. ± stool bulking agent.

  3. ± pelvic floor and toileting exercises (page 18).

Macroscopic colitis
  1. Send stool culture.

  2. If mild or moderate, refer within 2 weeks to a gastroenterologist. If severe, this is an emergency—discuss immediately with a gastroenterologist.

Microscopic colitisDiscuss with supervising clinician and refer to a gastroenterologist.
2nd Line
Colonoscopy with biopsiesMacroscopic or microscopic colitisAs above.
Organic cause (eg, infection, inflammation, neoplastic)Discuss with the appropriate clinical team within 24 h.
If diarrhoea is present in combination with other symptoms:
flushing, abdominal pain, borborygmi, wheezing, tachycardia or fluctuation in BP
3rd Line
Gut hormones (Chromogranin A&B, gastrin, substance P, VIP, calcitonin, somatostatin, pancreatic polypeptide) and Urinary 5-HIAA and CT chest, abdomen and pelvisFunctioning NET, eg, carcinoid syndrome or pancreatic NETDiscuss and refer to the appropriate neuroendocrine tumour team requesting an appointment within 2 weeks.
If all tests are negative, but symptoms persistReassure and suggest symptomatic treatment with antidiarrhoeal drugs.
Trial of low-dose tricyclic antidepressants.
  • Note: faecal calprotectin as a marker for bowel inflammation is too non-specific and hence not recommended in this population.

  • BAM, bile acid malabsorption; EPI, excocrine pancreatic insufficiency; GP, general practitioner; IgA, immunoglobulin A; IgG, immunoglobulin G; OGD, oesophago-gastroduodenoscopy; PPI, proton pump inhibitor; NET, neuroendocrine tumour; SIBO, small intestinal bacterial overgrowth.