Diarrhoea, Constipation, Appendicitis and Diverticulitis Flashcards
(31 cards)
Compare the 2 broad causes of Diarrhoea in;
- Stool volume
- Response to fasting
- Stool osmolality
- Ion gap
Osmotic;
- Moderately increased
- Diarrhoea stops
- Normal to increased
- > 100mOsm/kg
Secretory;
- Very large
- Continues
- Normal
- <100mOsm/kg
Briefly outline the Secretory cause of Diarrhoea
- Electrolyte transport abnormal
- Secretion of Cl/ HCO3 into Lumen of gut
- Na follows and so does H2O
Suggest 3 non-osmotic, non-secretory causes of Diarrhoea
Insufficient Na absorption from gut lumen;
- Reduced SA for absorption
- Mucosal disease/ bowel resection (Coeliac, IBD)
- Reduced contact time (Intestinal rush)
What are 4 risk factors for Constipation
- Female (3:1)
- Certain medications
- Low levels of physical activity
- Increasing age (also common <4)
What are 3 types of causes of Constipation
- Normal Transit Constipation
- Slow Colonic Transport
- Defecation problems
What causes Normal Transit Constipation?
List 2 causes of Defecation problems
- Psychological stress
- Cannot coordinate muscles of defecation
- Disorders of Pelvic Floor/ Anorectum
List 5 cause of Slow Colonic Transport
- Large colon (Megacolon)
- Fewer an shorter peristaltic movements
- Nervous system diseases (MS, Parkinson’s)
- Systemic disorders (diabetes, hypothyroidism)
- Fewer Interstitial cells of Cajal (intestinal pacemaker cells)
List 5 treatments of Constipation
- Psychological support (If Normal Transit Constipation)
- Increased fluid intake
- Increased activity
- Increases fibre intake (Only useful if mild)
- Laxatives (Osmotic, Stimulatory, Stool softeners)
Describe the Appendix (including itself, its muscle, blood supply)
- A diverticulum of the caecum
- Has a complete longitudinal layer of muscle (colon has incomplete bands called Teniae Coli)
- Blood Supply: Branch of Ileocolic branch of SMA, that comes up through a mesentery (mesoappendix)
Why is the location of the appendix important?
This changes the presentation of acute appendicitis
What are the 3 broad categories of Appendicitis?
- Acute (Mucosal oedema)
- Gangrenous (Transmural inflammation and necrosis)
- Perforated (Can-> Peritonitis)
Describe the classic explanation for Appendicitis
- Blockage of Appendiceal Lumen creates a raised pressure in the appendix
Causes venous pressure to rise (causing oedema in walls)->;
- Harder for arterial blood to supply appendix
- Ischaemia, then bacterial invasion follows
What is the alternative explanation for Appendicitis?
Viral or bacterial infection causes mucosal changes that allows bacterial invasion of Appendix walls
How does Appendicitis present classically? (<60% of cases)
- Poorly localised peri-umbilical pain
- Anorexia
- Nausea and vomiting
- Fever
- After 12 to 24 hrs, pain is felt more intensely in Right Iliac Fossa
Describe the pain changes in Appendicitis, considering that the appendix is intra-peritoneal
Initially;
- Appendix swells, stretching Visceral Peritoneum’s afferents
- Pain referred to T9/ T10 Dermatome
After 12-24hrs;
- Enlarges to touch wall of abdomen and irritate Parietal Peritoneum
- Pain localised to Right Iliac Fossa
Why may you not get Right Iliac Fossa pain if the Appendix is Retro-Caecal or Pelvic in position?
Where else may you get pain?
- RIF parietal peritoneum does not come into contact with inflamed appendix
- Supra pubic
- Right sided rectal
- Vaginal
Suggest 2 patient groups in which it may be harder to diagnose Appendicitis
Children;
- Difficult to get full accurate history
- Symptoms are more non-specific
Pregnancy;
- Altered anatomy
What are 5 signs of Appendicitis?
- Appear SLIGHTLY ill
- Slight fever/ tachycardia
- Lie quite still (to avoid irritation to peritoneum)
- Localised Right Quadrant tenderness
- Rebound tenderness in right iliac fossa (Pain felt on rebound_
Where is McBurney’s Point?
What is significant about it?
- 1/3 of way from ASIS to Umbilicus
- Generally this is where the Appendix lies
What are 2 treatments of Appendicitis?
- Open appendicectomy
- Laparoscopic appendicectomy
What is Diverticulosis?
Is it symptomatic?
Where do most occur?
The presence of Diverticula- Outpouchings of Mucosa and Submucosa herniation through Muscularis layers
- Asymptomatic
- Sigmoid colon, along where nutrient vessels penetrate bowel wall
State the suspected cause of Diverticula forming
Increased intra-luminal pressure (low fibre diet)
Compare Diverticulosis, Acute Diverticulitis and Diverticular Disease
Diverticulosis;
- Presence of Diverticula
Acute Diverticulitis;
- Inflammation/ perforation of Diverticula (+/- bleeding and abscess formation)
Diverticular Disease;
- Pain due to Diverticula, WITHOUT inflammation/ infection
What percentage of people with Diverticulosis develop Acute Diverticulitis?
Up to 25%
