Conditions of the Large Intestine Flashcards
What is constipation?
A bowel movement less frequent than 3 times per week
OR
Production of a stool which is hard, difficult to pass or painful to pass
What is more important for diagnosis of constipation?
Consistency as opposed to frequency
What does the Rome III (chronic dunctional constipation) criteria state?
Requires 2 or more of the following features that must apply to at least 25% of bowel movements over a 3 month period
- Straining or manual manoeuvres required to facilitate evacuation
- Lumpy/hard stools or if loose stools rare without laxatives
- Sensation of incomplete evacuation or anorectal blockage
- <3 bowel movement each week
What is the aetiology of constipation?
Dietary factors
- Diets low in fibre or water
Lifestyle factors
- Sedentary lifestyles
Medication side effects
- Analgesia, anti-depressants, iron supplements, diuretics
Psychological and neurological factors
- Chronic stress, ignoring the urge to defecate
Organic diseases and metabolic problems
- Diverticular disease, GIT malignancies, IBD, hypothyroidism
What are features that are concerning in regards to constipation?
Onset in middle age or old age
PR bleed, melena or mucous
Weight loss, fever, rectal pain, anorexia, nausea, vomiting
Family history of colorectal cancer
Vomiting
What is targeted management for constipation?
Increase fibre and water intake
Introduce gentle exercise
Drug regimen modification
Address psychological issues e.g. managing stress
Use of biofeedback or neuromuscular retraining
What does the pelvic floor do to support the visera and when would it do this?
Actively contracts during
- Cough/sneeze
- Vomiting
- Lifting heavy objects
- Forced expiration
It does this to support the viscera during periods of increased intra abdominal pressure
What is the role of osteopathy to help someone with constipation?
Visceral techniques
Implications of patient teaching
What is the muscle that holds the rectum and what angle is needed for it to relax?
Puborectalis muscle
- 35 degrees
What are first line therapy options for constipation?
Bulking agents: psyllium
Osmotic laxatives: lactulose, glycerol
How do bulking agents and osmotic laxatives work?
Bulking agents: increase faecal bulk which stimulates peristalsis
Osmotic laxative: exerts osmotic effect which increases intraluminal pressure
What other options are there for constipation?
Stool softeners: ducosate
- Promotes retention of water in faecal matter
Bowel stimulants: senna, bisacodyl
- Direct stimulation of nerve endings in colonic mucosa
*Avoid long-term use
What is irritable bowel disease?
Functional bowel disorder consisting of abdominal discomfort and constipation or diarrhoea (or an alternation between both) in the absence of organic disease or gross structural changes of the intestine
Complex disorder, and its cause is poorly understood
What is functional GIT disorder now referred to?
Disorder of gut-brain interaction
What is the incidence of IBS?
Most common bowel disorder in western countries
Affects up to 25% Australians, greater prevalence in <50
What are the proposed mechanisms of IBS?
Miscommunication between the gut and CNS
Abnormal intestinal motility (dysmotility) and secretion
Visceral hypersensitivity
Alterations on gut microbiota
Genetic susceptibility
In some people there is a correlation between symptoms and:
- Certain foods
- Recent intestinal infections or intestinal overgrowth
- Emotional/psychological factors e.g. stress
Symptoms of IBS frequently occur during or after a stressful event and stressful events in early life may predispose to the development of IBS
What are clinical features of IBS?
Abdominal pain or discomfort
- Common in right or left iliac region or hypograstrium
- Usually relieved by defecation
Variable bowel habit
- Predominant constipation/diarrhoea
- Alternating constipation/diarrhoea
Abdominal distension, excessive flatus and borborygmi (sounds made in tummy)
Nausea, cramping, tenesmus (feeling like you need to defecate even though bowels are empty)
What investigations are made to diagnose IBS?
Stool cultures
FOBT
Colonoscopy
How does loperamide work?
Opioid receptor agonist
- Binds to opioid receptors
- Slows down motility of bowel
- Allows water absorption to blood volume
Does not cross blood brain barrier
- Does not provide euphoria
Bad to take when you have bacteria such as gastro
- You want to excrete the bacteria from body not hold it in
How does hyoscine butylbromide work?
Relax smooth muscle Anti-cholinergic medicine
- Binds to muscarinic receptors
Decrease cramps = relax smooth muscle = anti-cholinergic = down regulating PNS
What is the appendix?
Blind intestinal outpouch arising from the posteromedial aspect of the caecum (inf. to the ileocecal junction)
6-10cm in length
Has a small twisted lumen
Is it intra or retro peritoneal?
Intraperitoneal and has a short mesentery or mesoappendix between the terminal ileum, caecum and appendix
What is McBurney’s point and where does it correspond with?
Corresponds where the appendix attaches to the caecum
What is the histology of the appendix?
Lymphoid tissue
What is the function of the appendix?
Immunity: produces and stores lymphocytes
Reservoir for beneficial gut bacteria
Helps to recolonise the gut when needed