GI Flashcards
(186 cards)
describe the initial steps of digestion
- Digestion starts with food being crushed and mashed into smaller pieces in the mouth.
- Amylase from the salivary glands begins the breakdown of carbohydrates.
- The food bolus is swallowed and propelled through the esophagus through the lower esophageal sphincter and into the stomach
- Digestion of fats starts in the stomach with lipase from gastric glands being secreted.
- Protein digestion begins when pepsin and HCL denature the proteins to produce large peptide fragments and some free amino acids.
Where do fats, proteins, and carbs start being digested
- carbs- mouth from amylase in saliva
- fats- stomach with lipase from gastric glands
- Proteins- stomach w/ pepsin and HCL
It is that about ___ after you start to eat, that your body initiates a gastro-colic reflex where your colon, rectum and anus are stimulated to evacuate.
15-20 minutes
Where are vitamin B1, B2, B3, B5, B6, folic acid, vitamin C, zinc and iron absorbed
- Vitamins B1, B5, B6 are absorbed in the jejunum and ileum.
- Vitamins B2, and B3 are absorbed throughout the small intestine.
- Folic Acid absorbed in the proximal jejunum.
- Vitamin C absorbed in the distal small intestine.
- Iron is absorbed primarily in the proximal intestine.
- Zinc is absorbed mainly in the ileum.
describe digestion in the SI
- fats are combined with bile salts and pancreatic lipase to create small, mixed micelles which are ultimately absorbed into the enterocytes and through to the lacteals. Fat soluble vitamins are absorbed this way (A,D, E, K)
- protein digestion in the duodenum
- starches are broken down into smaller components by pancreatic amylase
describe protein digestion in the duodenum
- Cholecystokinin is released which stimulates the pancreas to release protease zymogens (aka proenzymes) and the intestinal cells to release enterokinase.
- Enterokinase converts trypsinogen to its active form—trypsin.
- Trypsin activates more trypsinogen, chymotrypsinogen, proelastase and procarboxypeptidase A and B into their active forms. These enzymes are responsible for cleaving certain AA bonds thus creating smaller peptide chains that can be better absorbed.
- These peptide chains are further broken down by the brush border enzymes into single, di and tripeptides which are then transported in to the enterocyte.
- Intracellular peptidases will continue to convert these small peptides into individual amino acids that will be absorbed into the circulatory system.
describe starch break down in the SI
Starches are broken down into smaller components by pancreatic amylase. These disaccharides are further broken down by brush border enzymes such as lactase, sucrase, maltase, isomaltase, and trehalase and then transported into the cell. Highest activity of these enzymes in the proximal intestine.
Chronic abdominal pain is abdominal pain lasting longer than ___
6 months
HPI questions that will help you sort through your differential diagnosis when seeing a child for chronic abdominal pain
- Stooling pattern. How often are they stooling? What does the stool look like? Do they see blood and/or mucous in the stool? You’ll also want to know if stooling makes the pain better or worse?
- You’ll want to ask about the location of the pain.
- Are there signs that indicate something organic is taking place—vomiting, weight loss/weight gain, fevers, waking at night because of pain or symptoms, etc?
- Does food make the pain better/worse? Does stress seem to exacerbate the pain?
PMH questions to help you assess abdominal pain
- Did the child pass meconium within the first 48 hours?
- Does the child have other associated medical conditions that increase the risk of certain GI diseases—atopy (allergies/asthma/eczema), cystic fibrosis, diabetes, down’s syndrome, etc?
- Is the child on medications that can contribute to abdominal pain, and/or diarrhea and constipation (iron, antibiotics, antidepressants, ADHD meds, psych meds, etc)?
- What kind of surgeries has the child had—imperforate anus repair, tethered cord release, spina bifida, intestinal resections, etc?
Fhx questions to ask to help you asses abdominal pain
- Is there a family history of other GI conditions?
- Atopic family history?
- Autoimmune family history?
2 main GI conditions you’ll see in infants
- GERD
2. Milk protein intolerance
Who do we see milk protein intolerance most commonly in
- in infants anywhere from 1-2 weeks of age to about 9-10 months of age.
- Typically it occurs in breastfed infants who present with fussiness anytime throughout the day and not just in the evenings.
Presentation of milk protein intolerance
- fussiness anytime throughout the day- not just PM
- Bright red blood or mucous in their stools
- Growing well- eating and gaining weight appropriately
what is milk protein intolerance due to?
-a combination of insufficient secretion of zymogens from the pancreas leading to incomplete protein digestion and an immature, leaky gut in the infant. The poorly digested proteins irritate the lining of the intestinal tract causing pain when the infant eats
tx of milk protein intolerance
- includes educating the family that this is a self-limiting condition (4-10 months of age)
- Maternal elimination diet can help
- If soy formula does not change the condition, you can do a 2 week trial of a semi-elemental formula like Nutramigen or Alimentum where the proteins are more hydrolyzed. (not liked as much by infants so transition by milking)
- If the child is still highly fussy, you can try a two week trial of elemental formula such as EleCare and Neocate
describe the prognosis of milk protein intolerance
- Self-limiting
- As the child grows and matures, the pancreas will reach adult secretory levels by a year of age and the tight junctions between the cells will work more effectively.
- Parents typically start to see improvement around 4-6 months of age but some kids can take up to 10 months for improvement in their symptoms.
describe how maternal elimination diet can help milk protein intolerance
- Start with a two week trial of eliminating one food at a time—dairy first, then soy and finally peanuts. If no improvement is seen after eliminating those three foods, you can do a trial of a soy formula for 2 weeks.
- Unfortunately 50% of kids that react to breast milk or regular formula will also react to soy.
One of the most common causes of chronic abdominal pain in kids is
constipation
define constipation
-a delay or difficulty in defecation present for 2 or more weeks. The average child will stool 1-2 times a day unless they are in the first few weeks of life where they can stool 1-4 times a day.
what are the peak times of constipation occurence
- 6 months of age with the introduction of solids
- 1-2 years of age with the introduction of cow’s milk
- 3-5 years of age with the challenge of kids not wanting to stool at school
You will want to make sure the child passed meconium within the first ___ or you are likely dealing with a condition other than chronic constipation
48 hours
Red flags for other abdominal conditions that are not constipation/encopresis
- not passing meconium in 1st 48 hrs
- fever
- vomiting
- failure to thrive
- anal stenosis
- tight empty rectum on PE
- abdominal distention
The North American Pediatric Gastroenterology, Hepatology and Nutrition association recommends one treatment regimen for kids UNDER a year of age with chronic retentive constipation:
- Education: explain the process of constipation
- Diet: can introduce 2-4 oz of sorbitol containing fruit juice into diet or feed pureed prunes
- Medication: If diet and education are not helpful, consider a trial of an osmotic laxative like Lactulose or Karo syrup (1-2 tablespoons QD-BID—titrating to achieve soft pudding consistency stools)
- Can add in ½ dropper of Little Tummies laxative if necessary for 2 weeks if child is very retentive