Gastrointestinal Flashcards
Colorectal cancer
Risk factors, pathophysiology, types, manifestations, diagnosis, treatme
Risks: low physical activity, high BMI, alcohol, smoking, high fat and red meat, low fibre
Pathophysiology: genetic and environmental factors contribute to benign adenoma polyps, which slowly develop into neoplastic and malignant polyps or carcinomas that invade lining
Types:
* Right tumours (caecum & ascending colon) are large, bulky, palpable and cause anaemia,
* Left are small button masses that ulcerate, cause bleeding, hard stool and obstruction
Manifestations: pain, mass, anaemia, bloody stool, obstruction, distention
Dx: faceal occult, colonoscopy, CT
Tx: resection, chemo, radiation
Ulcerative colitis
Description & brief pathophysiology, manifestations
Chronic inflammatory disease causing ulceration of the colonic mucosa, absess formation and necrosis, usually rectum and sigmoid colon, that is immune mediated
Manifestations: diarrhoea, bloody stool, cramping, dehydration, weightloss, through regular relapse and remission
Crohn’s disease
Inflammatory condition similar to UC but affects the entire intestinal wall of both large and small intestine (rarely rectum), also immune mediated and genetic predisposition, that causes ulcerations, skip lesion fissures, fitsulae, strictures and obstructions
Manifestaions: no specific symptoms, but signs of irritable bowel such as diarrhoea, occasional bleeding, abdominal pain and weight loss, nutritional deficiencies
Peptic ulcer
Description, causes, types (list)
Ulceration in the mucosal lining of the stomach or duodenum caused by excessive acid secretion or disruption in mucosal barrier caused by infection, NSAIDs, alcohol
Gastric, duodenal, stress
Gastric ulcers
Description, main causes, symptoms
- Ulcers of the stomach that occur in the antrum, near parietal cells, and are chronic
- Acid production is normal but mucosa is breached due to drugs, infection, gastritis, or duodenal reflux
- Intermittent pain in epigastric region that is alleviated with food
Duodenal ulcers
Description, main causes, symptoms
- Most common, caused by increased pariatel cells, elevated gastrin, gastric emptying and infection
- Relapse/remission rather than chronic, and they heal spontaneously
- Symptoms of epigastric pain, esp when stomach is empty, blood in vomit or stool
Stress ulcer
Description, main causes, symptoms
- Acute peptic ulcer due to severe illness, trauma, neural injury or emotional stress, that occurs at multiple sites
- Bleeding is the main symptom
Malnutrition
Lack of nourishment from inadequate amounts of calories, protein, vitamins and minerals, due to improper diet or alterered digestion/absorption
Starvation
Extreme malnutrition and hunger from lack of nutrients
* Short term: 3-4 days, stimulates release of stored glucose and production from non-carb molecules
* Long term: breakdown of ketones and FAs, eventual proteolysis and death if not restored
Failure to thrive
- Inadequate physical development of an infant or child, causing deceleration of weight gain, low weight-height ratio, and head circumference
Intestinal obstruction
Description, types, causes
Any condition that prevents normal flow of chyme through the lumen, can be** simple** (most common - mechanical blockage) or **functional **(motility failure)
Causes:
* Hernia (protrusion of intestine through weak abdominal muscles)
* Intussusception (part of intestine slips/telescopes into itself)
* Volvulus (twisting)
* Diverticulosis (small bulges due to lining weakness)
* Paralytic ileus
Vomiting/emesis
- Forceful emptying of the stomach by GI contraction aand reverse peristalsis of the oesophagus
- preceded by N and retching
- Projectile vomiting caused by direct stimulation of vomiting centre in brain
Diarrhoea
Description, causes, manifestations
- Increase in frequency of defecation, and fluidity and volume of faeces (>3x/day)
Causes:Excessive fluid drawn in by osmosis, excessive secretion of fluids by mucosa, or excessive motility
Rotarivus can cause severe diarrhoea in children
Gastrointestinal bleeding
Types, signs
Upper GI: oesophagus, stomach or duodenum (ulcers, retching)
* Haematemesis, black stools (melaena), +occult
Lower GI: jejunum, ileum, colon, rectum (polyps, IBD, cancer, haemorrhoids)
* Haematochezia (frank bleeding from rectum)
Abdominal distension
Swelling of the abdomen, occuring in bowel hypermobility, fluid accumulation in peritoneal cavity (ascites - portal hypertension, low albumin), bowel obstruction