lower GI therapeutics

• what is the definition of diarrhoea?

  • 'the passage of 3 or more loose or liquid stools per day (or more frequent passage than is normal for the individual)'
• what can diarrhoea be further categorised as?

  • Acute
  • Persistent
  • Chronic
• when is diarrhoea categorised as being acute?

  Less than 14 days
• when is diarrhoea categorised as being persistent?

  More than 14 days but less than 28 days
• when is diarrhoea categorised as being chronic?

  more than 28 days
• what does it mean if diarrhoea lasts more than 28 days?

  Chronic diarrhoea - not a disease but a sign/symptom of an underlying problem
• what are the underlying causes of diarrhoea in general?

  • Increased osmotic load in the gut lumen
  • Increase in secretion
  • Inflammation of the intestinal lining
  • Increased intestinal motility
  • more than one mechanism can cause diarrhoea
• in adults and children, how many episodes of acute diarrhoea does one usually have?

  adult - approx 1 episode per year

  children - less than 5, 1-3 episodes per year
• what are some causes of acute diarrhoea?

  • Usually due to infection or ingestion of toxinsInfection:
  • Bacterial e.g. Campylobacter, Escherischia coli, Salmonella
  • Viruses e.g. rotavirus or norovirus
  • Other causes drugs, parasites, anxietyNotifiable diseases:
  • Dysentery
  • Food poisoning
• with most cases of acute diarrhoea, when does it resolve?

  within 72 hours
• what are the symptoms of diarrhoea?

  • Loose or liquid stools
  • Increased frequency – 3 or more times per day
  • Abdominal cramping
  • Flatulence - wind
  • Mild abdominal tenderness
  • Usually rapid in onset
• what is travellers diarrhoea?

  • a type of acute diarrhoea
  • Diarrhoea experienced by travellers or holiday makers
  • Consider destination, age, diet
  • Early onset, usually within the first few days of the trip
  • Usually resolve within 7 days
• what can help prevent travellers diarrhoea?

  advice on hygiene, food and drink
• what are the symptoms of travellers diarrhoea?

  as per acute diarrhoea but can also have bloody diarrhoea (dysentery)
• what are the potential causes of chronic diarrhoea?

  • irritable bowel syndrome (IBS)
  • Inflammatory bowel disease (IBD)
  • Malabsorption syndromes e.g. coeliac disease
  • Metabolic disease e.g. diabetes, hyperthyroidism
  • Laxative abuse
• what should you ask about to help get a diagnosis for diarrhoea?

  • Nature e.g. blood, mucus
  • Occurrence – isolated or recurrent
  • Duration
  • Onset – how quickly developed
  • Timing
  • Diet and food
  • Recent travel
  • Medication – lots of medicines can cause diarrhoea
• what are the mild signs of diarrhoea?

  tiredness, nausea, light-headed, anorexia
• what are the moderate signs of diarrhoea?

  • Dry mouth, sunken eyes
  • Decreased urine output, feeling thirsty
  • Decreased skin turgor (pinch test)
• when would you refer someone who has diarrhoea?

  • Associated severe vomiting and fever
  • Recent travel to tropical/subtropical climate
  • Blood or mucus in stools
  • History of change in bowel habit (especially if > 40)
  • Severe pain/rectal pain
• when would you refer someone who has diarrhoea looking at the duration of symptoms?

  • Symptoms:
  • > 72 hours (3 days) in healthy adults
  • > 48 hours (2 days) in elderly
  • > 24 hours (1 day) if diabetic
• what is the treatment for acute diarrhoea?

  • Most cases - self-limiting and resolve within 2- 4 days
  • Stay at home, rest and let it "run its course"
  • Can give treatments for symptomatic relief
  • The primary aim is to prevent dehydration and re-establish normal fluid balance - via first-line treatment: Oral Rehydration Therapy
• how is oral rehydration therapy prepared?

  ORS packets.

  • Number of different preparations available
  • Sachets that are dissolved in water – make up to the recommended volume
  • Usually, dose is 200-400ml after very loose motion
• If diabetic - monitor blood glucose levels carefully if they are on oral rehydration therapy
• what is another way to treat diarrhoea?

  Give treatments that alter gut motility - this is if staying at home and resting is impractical or inconvenient
• what options are available for the treatment of diarrhoea that helps alter gut motility?

  • Loperamide
  • Morphine (low dose in combination with other treatment)
  • Diphenoxylate
  • Adsorbents e.g. bismuth subsalicylate, kaolin
  • Antibiotics (if appropriate)
• Loperamide mechanism of action...

  • Synthetic opioid analogue - µ (mu) opioid receptor agonist
  • Direct action on opiate receptors in the gut wall
  • Reduces propulsive peristalsis - increasing intestinal transit time and enhancing resorption of water and electrolytes
  • Increases the tone of the anal sphincter - helps reduce faecal incontinence and urgency
  • Slows down gut transit time
  • Extensive first-pass metabolism therefore little reaches systemic circulation
• morphine...

  • Direct action intestinal smooth muscle
  • Morphine content per recommended dose of products available OTC for diarrhoea ranges 0.5-1mg - ? effective
• adsorbents...

  • Adsorb microbial toxins and micro-organisms
  • Kaolin (Kaolin and Morphine)
  • Bismuth subsalicylate (Pepto-Bismol liquid)
• antibiotics (diarrhoea)...

  Stool sample should be taken and causative organism identified before antibiotic given
• what is the general management for diarrhoea?

  • Plenty of clear fluids
  • Avoid drinks high in sugar
  • Avoid milk and milky drinks
  • Eat light, easily digested food
• What's the definition of constipation

  • Defaecation that is unsatisfactory because of infrequent stools, difficult stool passage, or seemingly incomplete defaecation
  • Passage of hard stools less frequently than normal - change to normal habit
  • Typically less than three bowel movements in one week
• Constipation is more common in...

  • Women, particularly if pregnant
  • Older people
• what is the pathophysiology of constipation?

  • GI mortality reduces
  • Large intestine:
  • Removes water and salts from the colon (more water is reabsorbed)
  • Drys and expels faeces
  • In constipation – increased water resorption leads to harder stools more difficult to pass
  • Mainly due to the increased intestinal transit time of food
  • Occasionally – ignore defecation reflex
• what are some causes of constipation?

  • Functional (idiopathic)
  • No anatomical or physiological cause known
  • Secondary
  • Induced by a particular condition or medicine
  • Non-medical factors e.g. fibre, lifestyle, environment
  • Medical conditions
  • Medications
• what are the symptoms of constipation?

  • Abdominal discomfort and distension
  • Abdominal cramping
  • Bloating
  • Nausea
  • Difficulty passing stool
  • Specks of blood due to straining (bright red specks in toilet or on tissue)
• what do you ask about to help diagnose constipation?

  • Usual bowel habit (compare current to "normal")
  • Stool frequency and appearance - has it happened before
  • Nature e.g. blood mixed in stool, black, tarry stool, mucus
  • Occurrence – isolated or recurrent
  • Pain on defecation
  • Duration
  • Onset
  • Diet and food
  • Recent travel
  • Medication – lots of medicines can cause constipation
  • Medical history
• what are the red flags of constipation?

  • has a it for more than 2 weeks - unusual so there might be an underlining cause that needs to be looked at
  • Unexplained weight loss
  • Blood in stools
  • Rectal bleeding
  • Family history of colon cancer or IBD
  • Signs of obstruction
  • Nausea, vomiting or abdominal pain
  • Age > 40 and marked change in habit with no obvious cause
  • 14 days duration
  • Tiredness
  • Alternating with diarrhoea (can be related to IBS?)
  • Pain on defecation which may cause person to suppress reflex (common in kids) - leads to problems in the GI tract
• what does treatment for constipation aim for?

  • Restore normal frequency/bowel habits
  • defecation
  • Achieve regular, comfortable defecation
  • Avoid laxative dependence
  • Relieve discomfort
• what's the non-pharmacological treatment for constipation?

  • Consider primary cause
  • Diet, increase fluid intake and lifestyle measures including exercise - to maintain a fluid balance
• what's the pharmacological treatment for constipation?

  Laxatives