Table 11

Inestigation and management of diarrhoea

InvestigationsPotential resultsClinical management plan
Actions from history, medication and dietary assessment
History findingsSmokingLifestyle advice about smoking cessation.
AnxietyConsider referral for psychological support.
Dumping syndromeSee p. 20.
Medication findingsDrug induced: eg,
  • PPIs

  • Laxatives

  • β blockers

  • Metformin

Medications advice.
Dietary findingsLow/high fibre intake, high fizzy drink intake, high use of sorbitol containing chewing gum or sweets, high caffeine intake, high alcohol intake
  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 and alcohol/caffeine reduction.

First line
Routine and additional blood testsAbnormal resultsFollow treatment for abnormal blood results (p. 2).
Mg2+ lowFollow treatment for abnormal blood results (p. 2).
Coeliac diseaseRefer to coeliac clinic/dietitians/gastroenterology.
Stool sample for microscopy, culture and Clostridium difficile toxinStool contains pathogensTreat as recommended by the microbiologist and local protocols.
Stool sample for faecal elastaseEPIManagement of EPI (p. 26).
OGD and SI aspirate (p. 25) and SI biopsiesSIBOManagement of SIBO (p. 27).
Coeliac diseaseRefer to coeliac clinic/dietitians/gastroenterology.
Other GI pathologyDiscuss with supervising clinician within 24 hours.
Glucose hydrogen methane breath testSIBOManagement of SIBO (p. 27).
Carbohydrate challengeCarbohydrate intolerance/malabsorptionManagement of carbohydrate malabsorption (p. 26).
SeHCAT scanBAMManagement of BAM (p. 25).
Colonoscopy with biopsies (if frail, consider flexible sigmoidoscopy instead of colonoscopy)Macroscopic colitisSend stool culture.
If mild or moderate, refer urgently to gastroenterology.
If severe, this is an emergency. Discuss immediately with a gastroenterologist.
Microscopic colitisRefer to gastroenterology.
MalignancyRefer urgently to the appropriate MDT requesting an appointment within 2 weeks.
Second line
Gut hormonesFunctioning NETRefer to the appropriate NET team requesting an appointment within 2 weeks.
Third line
If normal investigations/no response to interventionRefer to gastroenterology.
  • BAM, bile acid malabsorption; EPI, exocrine pancreatic insufficiency; GI, gastrointestinal; MDT, multidisciplinary team; Mg2+, magnesium; NET, neuroendocrine tumour; OGD, upper GI endoscopy (oesophago-gastroduodenoscopy); PPI, proton pump inhibitor; SeHCAT, 23-seleno-25-homotaurocholic acid; SI, small intestine; SIBO, small intestinal bacterial overgrowth.