gastrointestinal system

What is the digestive system responsible for?

• consumption of food

• elimination of waste

• digestion

functions of gi/digestive system

provides nutrients, water, electrolytes and supports physiological activities

Alimentary canal

oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, anus

Accessory organs

salivary glans, liver, gallbladder, bile ducts, pancreas

Disorder of GI system

nutritional deficits, metabolic imbalances

Mild(constipation)→life threatening(pancreatitis)

vague symptoms, nonspecific manifestations

innermost layer of GI

-produces mucus

-protects tissue from acidic env(stomach 1-3)

-facilitates movement of contents

-high cell turnover due to erosion and acidity

peristalsis (muscle layer)

moves food in a wave like motion

atrophic gastritis

stomach lining may shrink and become inflammed

achlorhydria

reduced stomach acid production

Consequences of stomach changes (atrophic gastritis & achlorhydria)

slower digestion, vitamin b12 defiency

Liver changes

• reduced blood flow and slower drug clearance→bowel obstruction

• decreased regenerative capacity of liver cells

Small intestine changes

Reduced absorption of:

• calcium→risk of bone loss/osteoporosis

• Iron→absorption may decline

• lactose→ less lactase enzyme, harder dairy digestion

Motility chnages

decrease peristalsis→ higher risk of constipation

Altered Nutrition

problems with:

• consuming (cleft lip)

• digesting (pancreatitis)

• absorbing (celiac disease)

Result: inadequate nutrition→ underweight, vitamin deficiencies

can also contribute to elimination problems

Impaired elimination

results in constipation or diarrhea

Congenital defects

• often upper Gi tracts

• common, not usually life threatening

can cause nutritional problems, and self image issues

Cleft lip and palate

congenital oral defects visible at birth, can occur separately or together

Cleft lip and palate complications

• facial appearance changes

• feeding difficulties

• speech probs

• ear infections(otitis media) and hearing issues

Cleft lip

Results from failure of maxillary processes and nasal elevation/upper lip to fuse during development

unilateral or bilateral

Cleft palate

result from failure of hard and soft palate to fuse

creates opening bw oral and nasal cavities

Associate problems w/ cleft palate

• teeth and nose malformation present

• feeding problems = difficulty sucking

• high risk of aspiration if nasal cavity open

• impaired speech dev. due to inability to form sounds

Emesis(vomiting)

forceful ejection of chyme from the stomach through esophagus and mouth

voluntary and involuntary

Causes of emesis

• protective response (drug overdose, infection)

• reverse peristalsis (intestinal obstruction)

• increased intracranial pressure (projectile vomiting)

• associate with severe pain (migraines, renal calculi)

• stimulated by drugs, toxins and chemicals

what is emesis controlled by

medulla

precursors of emesis

nausea, retching

Effects of recurrent vomiting

• exhaustion due to strong muscular contractions

• fluid, electrolyte, and ph imbalances

Aspiration risk

• chyme entering the lungs can cause damage and inflammation

• higher risk if supine or unconscious

• can occur when vomiting/cough reflex surpassed by

  • drugs(anesthesia, narcotics)

  • disease(stroke)

Vomitus

contents that are vomited, characteristics indicate underlying causes

hematemesis

• appears brown and granular(coffee grounds) due to partial digestion of protein

• blood irritates gastric mucosa→ stomach expels it

Causes of hematemesis

upper gi bleeding (gastric ulcers, esophageal varices)

bile stained vomitus

• yellow or green color

• suggests gi obstruction

fecal colored vomitus

• deep brown color

• indicates content from lower intestine

• often results from intestinal obstruction

diarrhea

increased frequency, amount and water content of stool

what can diarrhea result from?

secretory: increased fluid retention

osmotic: decreased fluid absorption

motility: altered GI peristalsis

Acute Diarrhea

less than 3, loose/watery stools in 24hrs

chronic diarrhea

lasts longer than 4 weeks

causes of acute diarrhea

• viral infections: rotavirus, norovirus

• bacterial infections: salmonella, C.difficille, shigella. campylobacter, e.coli

• Medications: antibiotics, antacids, laxatives

• parasitic infections: giardia, s.dysenteria, V.cholerae

• usually self-limiting

causes of chronic diarrhe

• inflammatory bowel disease: crohn’s disease, ulcerative colitis

• malabsorption syndrome: celiac disease

• endocrine disorders: thyroid disorders

• chemo or radiation

Frank Blood (blood in stool)

bright red on surface

occult blood (blood in stool)

small, hidden amount

melana (stool in blood)

dark, tarry stool from upper GI tract

Clinical Manifestations of Diarrhea(small intestine)

-large, loose stool'

-often provoked by eating

-pain in right lower quadrant

Clinical Manifestations of Diarrhea(large intestine)

-small infrequent stool

-pain and cramping in left lower quadrant

clinical manifestations (acute diarrhea)

-cramping, fever, chills, nausea, vomiting

-stool may contain blood, pus or mucus

treatment of acute infectious diarrhea

• fasting mat help(food slows GI motility→increases bacterial/viral toxins)

• antidiarrheal agents

• antibiotics

treatment of noninfectious diarrhea

• antidiarrheal agents slow GI motility and increase fluid absoprtion

• anticholinergic and antispasmodic agents

Dietary management of diarrhea

• clear liquid diet until diarrhea subsides

• gradually advance to regular diet as tolerated

Management of Diarrhea

• probiotics (yogurt, buttermilk, kimchi, sauerkraut, supplements)

• dietary fiber(manage chronic diarrhea acts as a sponge)

• hydration and electrolytes

• skin care → bowel incontinence + helps maintain skin integrity

Constipation

change in bowel pattern w infrequent stool passage

stool remains in large intestine longer→ harder and more difficult to pass

causes of constipation

• low fiber diet

• inadequate physical activity

• insufficient fluid intake

• delaying urge to defecate

• laxative abuse

• stress

• travel

medical conditions of contstipation

• bowel diseases

• pregnancy

• medications (narcotics, anticholinergics, iron supplements)

• mental health issues (depression)

• neurologic disorders(stroke, parkinson’s disease, spinal cord injuries)

signs and symptoms of constipation

• pain during bowel movements

• inability to pass stool after straining >10 minutes

• no bowel movements for > 3 days

• hypoactive bowel sounds

treatment and prevention of constipation

• increase dietary fiber (veggies, fruit, whole grains) & hydration

• avoid constipating foods (processed sugar, white flour, red meat)

• increased physical activity

• use stool softeners (adds lipids and water to stool)

• limit laxatives and enemas

• digital removal of fecal impaction if necessary

Irritable Bowel Syndrome (IBS)

• chronic functional GI disorder

• characterized by altered bowel patterns & abdominal pain

• exacerbated by stress

• non inflammatory and does not cause permanent intestinal damage(unlike IBD)

IBS Theories

• altered Gi motility → increased intestinal contractions

• Visceral hyperalgesia → low intolerance for intestinal stretching/pain

• psychopathology → stress and psychological factors