Embed Size (px)
Citation preview
Dietary Management of GI Disorders Dietary Management of GI DisordersELENA TEJEDOR RD, CNSCSurgery, GI, ENTELENA TEJEDOR RD, CNSCSurgery, GI, ENT
1
Goal
2
Stomach & Pylorus(1)
Digestion Gastric acid - denatures proteins, acts as an Antimicrobial - activates pepsin (optimal pH 1.8 -3.5) - increases bioavailability of calcium, iron, B12Gastric Lipase (optimal pH 4.5-6) - Digests 10-25% of dietary TG - Secretion ↑ 3x-4x, incompletely compensating for pancreatic lipase deficiency
Secretion2-3L/d
-Begins with sight, smell,& thought = Cerebral phase ~40% of gastric secretion
Gastric fluids=HCl acid, IF, KCl, NaCl, gastric lipase,HCO3, mucin 3
Stomach & Pylorus(1)
Reservoir - Stores (1.5-2L)- Grinds < 2mm -Dispenses chyme. Rate determined by: pH, osmolality, consistency, lipid, calorie content ~150kcal/hr, Ileal brake feedback
Absorption Niacin, copper, ETOH, drugs
4
Small Bowel – Duodenum(1)
Length ~30cm (12 inch)D1-D4
Digestion Fat digestion – critically dependent on simultaneous release of bile salts + pancreatic lipase + calipase, and pHCHO + Protein digestion – Dependent on combined action of pancreatic enzymes + brush boarder enzymes +pH
Absorption Calcium,Copper, Iron (10% of PO Iron is absorbed enterically),Folate, Vit D, Zinc (25% absorbed in duodenum + prox jejunum)B12-heptocorrin complex – cleaved by Trypsin, so B12 can bind to IF and be absorbed in Terminal Ileum 5
Gallbladder(1)
-Bile
SecretionD2
500-600 ml/day- 95% re-absorbed in Terminal Ileum by active transport & re-cycled via portal circulation (2x/meal)- Maximum bile synthesis 5-10mmol/d, Use 25-30mmol/d- Hepatic excretion of lipid-soluble xenobiotics, drug metabolites, and heavy metals
Digestion -Lipid digestion / absorption, and fat-soluble vit. absorption-Cholesterol homeostasis-Conjugated bile acids have limited permeability to cell membranes improving fat absorption. -Bile salts ppt at pH <5 6
Composition of Bile (1)
Components Concentration (mmol/L or otherwise stated)
Sodium 140-160
Potassium 3-8
Chloride 70-120
Bicarbonate 20-50
Calcium 1-5
Phosphate 0-1.2
Magnesium 1-3
Iron 2-72 umol/L
Copper 12-21 umol/L
B12, Vit A, Zinc ?
Bile Acids (67% of bile) 5-50
Bilirubin total (0.3% of bile) 1-2
Phospholipid (Lecithin) (22% of bile) 0.5-20
Cholesterol (4% of bile) .5-1
Glutathione 3-5
Glucose 0.2-1
Urea 2.2-6.5
Protein (g/dL) (4.5% of bile) .2-3g/dL 7
Pancreas(1)
Secretion Exocrine: 1.5-2.5 L/day of digestive enzymes, bicarb, water, KCL, NaCl-0.2-0.3ml/minute in rest, 4.0ml/minute post meal-Sham Feeding (chew + spit) triggers 50% of normal secretion-Effected by location of food entry, if pre-digested, and if enzymes are supplementedEndocrine Hormones –insulin, glucagon, somatostatin, pancreatic polypeptides
DigestionExocrine
Amylase (Active pH 6.7-7) & Lipase (Active pH 3.5-6)Trypsinogen -activated to trypsin by Enteropeptidase (Optimal pH 7.5-8.5)Procalipase -activated to calipase by trypsinBicarb 8
Small Bowel(1) Jejunum 2-3M, Ileum 3-4M
Secretion ~ 1.5LFluids/day secreted, ~6L Absorbed
Digestion ~90% all nutrient absorption occurs in the first 1-1.5M of SB.
Absorption Jejunal
Thiamine, Pantothenic Acid, Folic Acid, B6, Riboflavin, Vit A, Vit K, Niacin, zinc
AbsorptionIleal
Vit C, Vit D, B12, Vit K, seleniumB12 absorbed within 60cm terminal IleumBile Salts re-absorbed within 100cm terminal ileum
Adaptive Ability
Best in the Ileum -Significant growth of microvilli size & number, and bowel diameter.Special transit biofeedback mechanisms
9
Small Bowel Ileocecal region
Transit Time Ileal Brake –by way of “Neuro Hormone Mediators” delays gastric emptying & slows intestinal transit when undigested CHO and fat reach the ileocecal regionIC valve controls the amount and slows the passage of ileal contents into the colon
Adaptive Involvement
Prevents bacterial overgrowth- Limiting fluid losses & competition for B12
10
Absorption 1-1.5L fluid, K, Na, Oxalates, SCFA/MCT, calcium, Vit K, unconjugated Bile Salts
Transit Time Entry into colon at ~50ml/hr. ~20 hr Transit time (8hrs ascending colon, 8 hr transverse colon, 4 hrs descending colon)
Role in Adaptation
•Highly Adaptable(1/2 remaining colon = 50cm SB)•Increased fluid (5-6L) and electrolyte absorption•Colonic Bacteria ferment undigested CHO/Fibre forming ~500-1200kcals/day of short chain FA.•Qualitative and quantitative colonic flora changes increasing capacity to metabolize CHO
Large Bowel(1)
Length 1.5 Meters
11
The Diseased Gut
12
Nausea & Vomiting
13
OBSTRUCTIONSDuct Obstructions, Hernias, Volvulus,
Intussusception, Bowel Edema, Diverticulitis, Adhesions, Cancer
14
Bowel Dysmotility/ObstructionVagal Nerve Damage (Cranial Nerve X),Bowel Ischemia
15
Nausea & Vomiting
•Resolution of obstruction•Pain / NauseaMedications
•Vagal nerve damage vs. Ileus •Adhesion vs. edema
•Proximal vs. Distal GIT
Small frequent mealsLiquids – BlenderizedChew wellLow fibre/ Limit poorly digested foodsHigh pro High calNJ FeedsTPN
Things to consider when deciding where and what to feed.
16
Diarrhea & Bloating
17
Diarrhea & Bloating
18
Vitamins / Mineral Deficiency Risk Review
B12 Limited IF or gastric acid, TI disease, Bacterial Overgrowth
Folate Proximal SB disease/resection. Drugs
Iron Proximal SB resection Loss from Chronic bleed
Calcium Proximal SB resection, Limited gastric acidFat malabsorption (insoluble calcium soaps), Vit D deficiency
Sodium &Potassium
Increased losses from vomiting & diarrhea (rapid transit or bowel resection)
Magnesium Rapid transit, Fat malabsorption (luminal binding of Mg with fat)
A,D,E,K Fat malabsorption (limited bile, limited pancreatic enzymes)
Zinc Rapid transit, Proximal bowel disease (14mg/L stool)19
20
21
Resources
• http://www.hhsc.ca Search “The Dumping Syndrome
Diet” • http://www.hhsc.ca Search “Low Fat Diet”
• Http://www.pennutrition.com Search “Eating Guidelines for Kidney stones”
PGSD/Low Fat/Oxalate PGSD/Low Fat/Oxalate FoodsFoods
Diet Handouts: Visit • www.bccancer.bc.ca Search
“Low Fibre Food Choices for partial Bowel Obstruction”
• http://vch.eduhealth.ca Search “Nutrition After
Ileostomy Surgery”
• http://www.hhsc.ca Search “What to eat and drink
when you have a High Output ostomy”
Low Fibre Handouts Low Fibre Handouts
22
References
1. Feldman, Friedman & Bradt (2010). Sleisenger & Fordtrains Gastrointestinal and liver disease: Pathophysiology, diagnosis, management. (9th ed).
Philadelphia,PA: Elsevier
2. Rogers. C.L. (2013). Nutrition management of the adult with cystic fibrosis-Part 1 Practical Gastroenterology. (113), 10-24
Recommended Read: Parrish. C.R (2005) The clinician’s guide to short bowel syndrome. Practical
Gastroenterology. (31), 67-106.
23
