Diarrhoea

• What does the patient mean by diarrhoea?• Normal bowel habit• Frequency over 24h• Consistency – colour, steatorrhoea, offensive

smell• Blood/mucus mixed in• Associated wt loss or other symptoms:

– N&V– Abdo pain

Diarrhoea - questions

• Systemic symptoms – malaise, lethargy• Risk factors – foreign travel/recent

contacts• Infective causes ask about -

– Fever, weight loss, night sweats, malaise, anorexia, recent travel important

Investigation of diarrhoea

• Stool culture• Exclude causes

– Drugs– TFTs– Anti-endomysial antibodies

• Flexi sigmoidoscopy• Ba. Enema / colonoscopy• OGD

Types of diarrhoea

• secretory diarrhea• osmotic diarrhea• motility-related diarrhea• inflammatory diarrhea

Secretory diarrhoea

• increase in the active secretion OR an inhibition of absorption

• little to no structural damage • causes

– Cholera toxin

Osmotic diarrhoea• “Too much water”• Causes

– Malabsorption • Loss of pancreatic secretions (pancreatitis, CF)• Bile salt diarrhoea (bile into colon not GB)• Cealiac disease• Lactose/fructose intolerance

– Osmotic laxatives– Short bowel syndrome– Drugs (antibiotics, antihypertensives, chemotherapy

and antacids containing magnesium)– Radiation induced fibrosis– ALCOHOL (hangovers)

Motility disorders

• Rapid transit through bowel– Hyperthyroidism– Vagotomy– Diabetic neuropathy

Inflammatory causes• Infective

– Bacterial• Campylobacter, Salmonella, Shigella, and

Escherichia coli– Parasitic

• Giardia lamblia, Entamoeba histolytica, and Cryptosporidium

– Viral • rotavirus, Norwalk virus, cytomegalovirus, herpes

simplex virus, and viral hepatitis

Inflammatory causes

• IBD• Cancer

– mucin secreting tumours of large bowel– Hormone secreting tumours, e.g. serotonin

• TB

Causes of diarrhoeaColonic causes Small bowel causes

Inflammatory bowel disease Coeliac disease

Infective colitis – bacterial, viral High –output eg post small bowel resection

Left sided colon malignancy Terminal ileitis eg TB or Crohn’s

Ischaemic colitis

Overflow diarrhoea secondary to constipation

causes of persistent diarrhoea (>4 weeks)

• ulcerative colitis• Crohn's disease• irritable bowel syndrome (IBS)• lactose intolerance• coeliac disease • diabetes• pancreatitis

IBS

• Defn: at least 12 weeks of preceding 12 months of abdominal pain or discomfort + at least two of the following:

• relief by defaecation• onset with change of frequency of stool• onset with change in form of stool

IBS

• typically 20-30’s• female 2:1 male• estimated 10-20% incidence in UK• causes not defined

– visceral hypersensitivity– disturbed colonic motility– post infective bowel dysfunction

symptoms

• pain• bloating • flatulence• constipation +/- diarrhoea

coeliac

• immune response to gliaden in gluten• causes villous atrophy in small bowel• develop intestinal malabsorption

• children – diarrhoea, fatigue and failure to thrive

Coeliac disease in adults• unexplained iron-deficiency anemia • fatigue • bone or joint pain • arthritis • osteoporosis • depression or anxiety • peripheral parasthesia • seizures • missed menstrual periods • infertility or recurrent miscarriage • mouth ulcers • dermatitis herpetiformis

Associated genetic conditions

• type 1 diabetes • autoimmune thyroid disease • autoimmune liver disease (PBC)• rheumatoid arthritis • Addison’s disease• Sjögren’s syndrome,

Ix for coeliac

• Serum – anti-tissue transglutaminase antibodies

(tTGA) – anti-endomysium antibodies (EMA).

• HLA typing– HLA –DQ2, HLA DQ8

• Intestinal biopsy – OGD (duodenal/jejunal bx)

classification

• Marsh classification for coeliac disease– Marsh stage 0: normal mucosa – Marsh stage 1: increased number of intra-epithelial

lymphocytes, usually exceeding 20 per 100 enterocytes

– Marsh stage 2: proliferation of the crypts of Lieberkuhn

– Marsh stage 3: partial or complete villous atrophy – Marsh stage 4: hypoplasia of the small bowel

architecture

Marsh classification for coeliac disease

Constipation - questions• Normal bowel habit• Duration of constipation – chronic/acute• Previous episodes/alternating with diarrhoea? • Stool – blood/mucus/melaena• Tenesmus• Rectal disease – piles, pruritis, fissures• Weight loss & appetite changes• Cramps or bloating - ?Ca colon – obstruction• Cancer – Weight loss, fatigue, anorexia,

haemoptysis, fhx, smoking

Haematemesis - questions

• Characterise nature of haematemesis – fresh blood/coffee grounds

• Number of episodes/previous episodes• Volume of blood• Is there melaena or fresh blood PR?• Other symptoms – epigastric pain, wt loss, ↓

appetite• Risk factors – alcohol XS, peptic ulcer disease,

oesophageal varices, meds - warfarin

Causes of haematemesis

OesophagealOesophagitis, carcinoma, oesophageal varices, Mallory-Weiss tear, trauma, hiatus hernia

GastricGastritis, peptic ulcer, tumours

DuodenalDuodenitis, duodenal ulcer

Rectal bleeding - questions

• Duration of symptoms – yrs, months• Previous episodes or treatment• Is the blood:

– mixed in with stool– separate – found on toilet paper/splashes in

toilet bowl• Fresh or altered blood - ? Lower vs upper

GI bleed

Causes of rectal bleeding

Main differentials :

• Haemorrhoids (piles)• Colonic carcinoma• Diverticular disease / bleeding ulcer• Anal fissure• Anal carcinoma (rare)