Red flags that prompt further investigation:

• blood in the stool
• recent hospital admission/Abx therapy
• weight loss
• evidence of dehydration
• nocturnal Sx
• Iron deficiency anaemia

Change in bowel habit:

• Change in consistency - Softer, harder, diarrhoea, constipation
• Change in frequency

Diarrhoea

Clinical definition -

• 3 or more loose or liquid stools in 24 hours
• Stools that are more frequent than what is normal for the individual
• Classification:
  • Acute diarrhoea < 14 days
  • Chronic diarrhoea > 4 weeks

Usually acute:

• Gastroenteritis
• Diverticulitis
• Abx therapy
• Constipation causing overflow
• Acute on chronic disorder (IBD/IBS)

Usually chronic:

• Infective - If no recent travel, chronic diarrhoea is unlikely
• IBS
• IBD
• Colorectal cancer
• coeliac disease

Mechanisms of Diarrhoea -

• Secretory - ⬆️ fluid in bowel due to ⬆️ secretion or ⬇️ absorption e.g. cholera