Conditions of the Large Intestine Flashcards
What is the definition of chronic constipation?
2 or more of (over a 3 month period):
- straining or manual movements required
- lumpy / hard stools
- sensation of incomplete evacuation
- less than 3 bowel movements a week
What are the 5 medications used to treat constipation?
- bulking agents
- increase faecal bulk to stimulate peristalsis - osmotic laxative
- creates an osmotic effect which increases intraluminal pressure - stool softeners
- promotes retention of water in faeces - bowel stimulants
- directly sitmulates nerve endings in colonic mucosa - opioids antagonists
- competitive antagonist at GIT opioid receptors
What are the risk factors and red flags for chronic constipation?
Risk factors:
- dietary
- low fibre
- low water - sedentary lifestyle
- meds
- analgesics
- anti depressants
- iron supps
- diuretics - psycho
- chronic stress
- refusal - disease
- diverticulitis
- IBD
- GIT malignancy
Red flags:
- onset in middle to old age
- PR bleed
- Hx / family Hx colorectal cancer
- rectal pain
- weight loss / anorexia
- nausea, vomiting
- fever
What are the common causes, red flags and management strategies for diarrhea?
Causes:
- acute
- infectious gastroenteritis (salmonella, ecoli, rotavirus)
- dietary (allergies, bingeing)
- adverse drug reactions to antibiotics - chronic
- HIV
- intestinal disorders (IBS, IBD, coeliac)
- adverse drug reactions to alcohol abuse or other
Red flags:
- severe or worsening in patients over 70 or immunocomprimised
- bloody / mucoid / prurulent stool
- severe abdo pain
- SSX infection
Management:
- treat causative factor
- rehydration and electrolytes
- antibiotics for bacterial infections
- anti-diarrhoael agents (not if food poisoning present)
- synthetic opioids (reduce peristalsis by acting on GIT opioid receptors)
Describe the condition of IBS, including incidence, pathophysiology and SSX
- diagnosis of exclusion
- consists of abdo discomfort with constipation and/or diarrhea
Incidence:
- most common bowel disorder in West
- 10% Australians
- most common in women 20-40
Pathophysiology: (proposed):
- disturbance of ENS / ANS / CNS
- abnormal intestinal motility and secretion
SSX:
- abdo pain in Rt or Lt iliac region or hypogastrium
- pain usually relieved by defecation
- constipation and/or diarrhea
- abdo distension
- excessive flatus and borborygmi
- nausea
- cramping
- tenesmus
Describe the condition of diverticular disease, including incidence, pathophysiology, complications, SSX and management
Diverticulosis = saccular outpouching in colon wall
Diverticulitis = inflammation of pouches
Incidence:
5-10% across all ages, 30-50% in over 60
Aetiology:
- diet low in roughage (higher intraluminal pressures needed to move stool)
Pathophysiology:
- high intraluminal pressure causes outpouching of colonic wall
- most common site: sigmoid
Complications:
- abscess formation (can perforate bowel wall and cause peritonitis)
- fistula formation
- fibrosis (can obstruct bowel)
- haemmorhage
SSX:
- usually asymptomatic
- pain in left iliac fossa
- changes in bowel habit (constipation alternating with diarrhea)
- acute diverticulitis: severe pain, guarding, rigidity
What are management options for diverticulitis?
- antibiotics
- analgesics
- anti inflammatories
- IV fluids
- possibly naso gastric suction
Describe the condition of haemmorhoids, including types, classifications, risk factors, and SSX
Types:
a. internal (varicosity of superior rectal vein proximal to pectinate line)
b. external (varicosity of perianal venous plexus distal to pectinate line)
Classifications of internal:
1st degree - vein distended and may bleed but remains internal
2nd degree - prolapse during defecation but spontaneously reduces
3rd / 4th degree: prolapses remain protruding after defecation
Risk factors:
- anything that increases venous pressure
- low fibre diet increases intraluminal pressure neded to evacuate stool
- chronic cough
- obesity / pregnancy
- obstruction (neoplasia)
SSX:
- bright red bleeding
- prolapse
- variable pain
Complications:
- strangulation (haemmorhoids compressed by anal sphincter, acute pain)
- thrombosis
- persistent blood loss causes anaemia
Describe the condition of appendicitis, including incidence, pathophysiology, and SSX
- inflammation of appendix
Incidence:
- most common abdo surgical emergency
- 7-12% of pop
Pathophysiology:
- obstruction of lumen prevents proper drainage
- mucosal secretions continue and increase intraluminal pressure
- ulceration occurs and promotes bacterial invasion
- inflammatory response
- gangrene develops from thrombosis of luminal blood vessels
- perforation of appendix
SSX:
- abdo pain beginining in gastric region and increasing over 3-4 hours as inflammation spreads to parietal peritoneum
- nausea / vomiting
- anorexia
- fever
- altered bowel habits
Describe the condition of colorectal carcinoma
- 2nd most common malignancy, and 2nd highest cause of cancer deaths
Risk factors:
- low fibre, high fat diet
- tobacco use
- family Hx of CRC
- IBD
- familial adenomatous polyposis
Pathophys:
- most tumours develop in adenomatous polyps
Common sites:
- rectum, sigmoid, caecum & ascending colon
SSX:
- ulcerated polyps: bloody/ mucoid diarrhea, frank or occult bleeding
- low abdo pain
- palpable mass
- constipation if bowel restricted
Describe the condition of IBD, including description, aetiology, complications, and management
Inflammatory Bowel Disease
- chronic inflammatory disease affecting bowel
- Ulcerative Colitis or Crohn’s Disease
Aetiology:
- mix of genetics and environment
- autoimmnune dysfunction
- disrupted gut microbiota
Complications:
- increased risk for colorectal cancer
- fibrosis caused by repeated inflammation can obstruct bowel
- biliary tree disorders (cirrhosis, gallstones)
- renal disorders (kidney stones)
- skin disorders and eye disorders
- toxic megacolon in UC
Management:
- anti-inflammatories (corticosteroids, 5-aminosalicyclic acids)
- biological agents (anti TNFa antibodies)
- immunosuppressants
- anti-diarrhoeal agents
Describe the condition of Ulcerative Colitis, including pathophysiology and SSX
- one of the IBD conditions (chronic inflammatory disease of the bowel)
- affects colon only
Pathophysiology:
- inflammation begins in crypts of LI and spreads to mucosa
- small erosions form in mucosa and develop into ulcers
- healing with fibrosis leads to psudopolyp formation (clumps of granulomatous tissue)
- oedema and thickening of muscularis narrows lumen
SSX:
- series of remissions and exacerbations
- diarrhea and maybe constipation
- low abdo pain, tenderness, cramping
- tenesmus
- severe episodes: dehydration, tachycardia, fever, anaemia
Describe the condition of Crohn’s DIsease, including pathophysiology and SSX
- one of the IBD conditions
- chronic inflammatory bowel disease
- can affect any part of the GIT (most common in terminal ileum, ascending and descending colon)
Pathophysiology:
- inflammation begins in submucosa and spreads to entire thickness of intestinal wall
- chronic inflammation leads to development of granulomas
- intestinal wall adopts a cobblestone appearance (lines of ulceration surrounding areas of mucosal swelling)
SSX:
- can mimic IBS or peptic ulcer
- vary depending on site affected
- diarrhea
- abdo pain
- weight loss
What are the differences between Ulcerative Colitis and Crohn’s Disease?
Site affected:
- UC: affects LI / colon only
- CD: can affect any part of GIT
Thickness of inflammation:
- UC: inflammation restricted to mucosa and submucosa only
- CD: inflammation affects entire thickness of intestinal wall
Site where inflammation begins:
- UC: begins in crypts of LI and spreads to mucosa
- CD: begins in submucosa and spreads to entire wall
Most common sites:
- UC: sigmoid / rectum
- CD: terminal ileum, ascending and transverse colon