PATHOPHYSIOLOGYDISEASES OF THE DIGESTIVE SYSTEM

Manukau Institute of Technology

BN3-S1-2012

Common Manifestations of GIT Diseases

Pain/heartburn/discomfort Difficulty in swallowing Loss of appetite Nausea Vomiting Gaseous distension Diarrhoea Constipation Bleeding

Simple Classification

ITIT

Simple Classification

Infection Viral Bacterial fungal

Traumatic Inflammatory Tumour

Benign Malignant

Diseases of the Mouth

Infection: herpes simplex, thrush

Trauma: injuries, accidental biting, burns

(hot drinks)

Inflammation: aphthus ulcer

Tumour: lip cancer, tongue cancer

Dysphagia

Difficulty in swallowing

Dys: Bad

Phagia: eating/swallowing

Anorexia

Loss of appetite a: without orexe: appetite ia: state or act

Causes Psychosocial Side effects of drugs Diseases

Treatment Treat the underlying cause

Nausea

Unpleasant sensation Preceded by loss of appetite Usually followed by vomiting Usually associated with:

Sweating Pallor Tachycardia (increased heart rate) Salivation Vasoconstriction

Vomiting (emesis)

Forceful oral expulsion (throwing out)

of stomach and portions of small

intestine contents• Protective mechanism

• Usually preceded by nausea

• Can lead to complications (alkalosis,

dehydration, etc.)

Vomiting

The vomiting centre receives impulses from:

GIT

Cerebral cortex

Vestibular apparatus : motion sickness

Other factors:

Drugs and toxins

Hypoxia

Vomiting

Treatment of Nausea and Vomiting

Supportive measures

reassurance

avoidance of triggering factors

bed rest if necessary

rehydration, IV fluids

Treat the underlying cause

Gastroesophageal Reflux

The “return” movement of stomach contents

Can cause heartburn Usually mild If persists, can cause

GastroEsophageal Reflux Disease (GERD) which can lead to severe heartburns and may interfere with some activities

Diarrhoea

The (frequent) passage of loose stoolTypes: Acute or chronic Watery or bloody Osmotic diarrhoea

– Non-absorbable substances (fibre) draw excess water into the intestinal lumen from the vascular component (lactase deficiency)

Secretory diarrhoea– Mucosa of the gut secretes excessive amounts

of water and electrolytes into interstitial lumen in response to irritation (bacteria, inflammation)

GIT Bleeding

Manifests as blood in vomit or blood in stool Haematemesis:

Blood in the stomach is an irritant and causes vomiting. May be bright red or ‘ground coffee’ coloured

Haematochezia:Red blood (fresh looking) in stool usually indicates bleeding in lower bowel, below the cecum. May often be the result of bleeding hemorrhoids.

Melaena:Dark blood usually indicates bleeding above the cecum.

Occult:Hidden blood can only be detected in a lab (stool sample)

Diseases of the Stomach

GastritisInflammation of the gastric mucosaTypes: Acute

Extreme stress Drugs:

Aspirin NSAI Corticosteroid Alcohol

Infection: H. Pylori Chronic

Peptic Ulcer

A group of ulcerative disorders of the upper GIT that are exposed to acid-pepsin secretions.

Most common peptic ulcers:

• Gastric

• Duodenal

Peptic Ulcer

Lesions that do not extend through the mucosal lining are called erosions.

Causes:• Helicobacter pylori• Aspirin and other NSAIDs• Exposure to irritants (cigarette smoke, alcohol, caffeine)• Physiological stress: major operations, extensive burns,

severe diseases.

Peptic Ulcer

Diseases of the Small and Large Intestine

Infection Trauma Inflammatory Bowel Disease (IBD)

Crohn Disease Ulcerative Colitis

Tumour Others:

Irritable Bowel Syndrome (IBS) Diverticular Disease Intestinal Obstruction Malabsorption

Irritable Bowel SyndromeClick on the black area to watch the video

http://www.youtube.com/watch?v=eInvmxGhsko

Inflammatory Bowel Diseasehttp://www.youtube.com/watch?v=TSLKKzZ04Dk

Diseases of the Liver and Hepatobiliry System

Common Manifestations

Pain/heaviness/discomfort Nausea Vomiting Diarrhoea Jaundice Oedema and ascites Bleeding tendency Hepatomegaly (liver enlargement)

Other Manifestations

Telangiectasia

Spider nevi

Palmar erythema

Caput medusae

Fetor hepaticus

Muscle wasting

Gynaecomastia

Telangiectasia

Spider nevi

Caput Medusae

Palmar Erythema

Jaundice

Yellowish discolouration of sclera and mucous membrane due to increased serum bilirubin.

Causes: Pre-hepatic:

haemolytic anaemia Hepatic:

Infection Cirrhosis Cancer

Post-hepatic Gall bladder stones

Diseases of the Liver

Viral Hepatitis A B C D E

Liver cirrhosis Portal hypertension Hepatic cancer

Liver Damage

Alcoholic Liver Disease

Chronic Excess Alcohol Consumption

Hepatocellular Carcinoma

Infection Hepatic Encephalopathy

Liver Failure G.I. Bleeds

-Liver decreases the formation andrelease of lipoproteins

-Lipid accumulates in liver-Over time fat cells become surrounded by fibrous tissue

-Liver becomes firm and nodules form-The liver eventually shrinks and nodules become

surrounded by connective tissue

-Liver necrosis begins-Mallory's Bodies lead to fibrosis around cells and veins

-Hepatocytes become infiltrated with WBCs-Liver enlarges

-Scar tissue develops

Alcoholic Steatosis

Alcoholic Hepatitis

Alcoholic Cirrhosis

DEATH due to....

Liver Failure

Portal Hypertension

High pressure in the portal vein and its branches

Causes• Prehepatic: Blockage occurs in bloodflow to

the liver– Portal vein thrombosis

• Intrahepatic: Blockage occurs in bloodflow within liver– Cirrhosis

• Post hepatic: Increased pressure in inferior vena cava– Right heart failure

Portal Hypertension

• The vessels most susceptible to high portal

pressures are:

– Esophageal

• Veins bulge and protrude into the lumen of the esophagus.

Vessels may haemorrhage causing exsanguination and death

– Haemorrhoidal

• Causes haemorrhoids which may also rupture into the rectum

Cholelithiasis

Gall Stones

(chole) = bile

(lithia) = stone

(sis) = process

Caused by the precipitation of substances

contained in bile – particularly

cholesterol and bilirubin

Cholelithiasis

Factors that contribute to the formation of gallstones include: Excessive excretion of cholesterol from the

liver into bile obesity, pregnancy, oral contraceptive use,

drugs that lower serum cholesterol The presence of gallbladder “sludge”

pregnancy, starvation and rapid weight loss Malabsorption of bile salts

intestinal bypass surgery, ileal disease Inflammation of the gall bladder

Cholelithiasis

Most people experience no symptoms except when the stones obstruct the bile flow

Small stones can pass into the common bile duct causing symptoms of indigestion and bilary colic (a severe pain in the upper right section of the abdomen)

Large stones are more likely to obstruct flow and cause jaundice

References

Brown, D. & Edwards, H. (Eds). (2008). Lewis’s medical-surgical nursing: Assessment & management of clinical problems (2nd ed). Sydney, Australia: Elsevier-Mosby.

Craft, J., Gordon, L., & Tiziani, A. (2011). Understanding pathophysiology. Sydney, Australia: Elsevier-Mosby

Johnstone, C., Farley, A., & Hendry, C. (2006). Nurse’s role in nutritional assessment and screening – Part one of a two-part series. Nursing Times 102 (49), 28-29

Johnstone, C., Farley, A., & Hendry, C. (2006). Nurse’s role in nutritional assessment and screening – Second of a two-part series. Nursing Times 102 (50), 28-29

Mark A. Marinella. (2008) Umbilical Complications of Malignancy. Journal of Gastrointestinal Cancer 39:1-4, 37-41