GI Flashcards
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
The North American Pediatric Gastroenterology, Hepatology and Nutrition association recommends one treatment regimen For kids OVER 1 year of age with chronic retentive constipation:
- Education: explain the process of constipation and that treatment will be a long term process (4-6 months minimum)
- Diet: decrease milk intake; increase fiber (5+ age); increase clear fluids
- Behavioral changes: toilet time 15-20 min after meals
- Medication: If diet and education are not helpful, consider a trial of Lactulose or Miralax (1/2 capful/1 tablespoon-1 capful/2 tablespoons dissolved in 4-10 oz of clear fluid) QD to BID
- Can add in 1 dropper of Little Tummies laxative or ½-1 square of Chocolate Ex-lax QD to BID if necessary for 2 weeks-2 months
Be fairly aggressive in your treatment of constipation. The reason why is the possibility of a child developing ___
encopresis aka fecal incontinence
what is encopresis
- Defined as involuntary passage of fecal material in the underwear; typically the child has anywhere from 3-8 bowel movements in their underwear that they can’t control
- Due to long standing chronic retentive constipation that has gone untreated or undertreated
tx of Encopresis
- Education: explain the process of constipation and that treatment will be a long term process (4-6 months minimum but more likely a year); explain soiling is NOT voluntary
- Diet: increase fiber (5gm+ age); increase fluids; this is going to be the long term management plan
- Behavioral changes: toilet time 15-20 min after meals
- Disimpaction—remove impaction with enema followed by a bowel clean out over a 2 day period (bowel clean out consists of a clear liquid diet, Miralax 4 times a day and ExLax twice a day until the stool comes out clear liquid)
- Medication: Following bowel clean out, give Miralax (1 capful/2 tablespoons dissolved in 6-8 oz of clear fluid BID)
- Also add in 1-2 squares of Chocolate Ex-lax BID for 2 months then wean but continue on Miralax for another 6-12 months
what is celiac disease
- an autoimmune response to the gluten protein in wheat.
- The gluten triggers an antibody response in the proximal small intestine resulting in inflammation and destruction of the villi.
- The villous atrophy leads to a loss of absorptive surface and intestinal enzymes frequently leading to malabsorption and diarrhea.
*an underlying cause of chronic abdominal pain
sx of celiac disease
Wide range of sx
- anything from asymptomatic results found on screening tests
- bloating
- abdominal pain
- failure to thrive with diarrhea
what should you do if you suspect celiac disease
- order a Tissue Transglutaminase Antibody blood test and also get a serum IgA level.
- If the TTG level is elevated, it is suggestive of Celiac Disease, but it is recommended to confirm the diagnosis with an upper endoscopy given the long term risks of untreated or poorly treated Celiac Disease (osteoporosis, intestinal lymphoma, infertility)
long term risks of untreated or poorly treated Celiac Disease
- Osteoporosis
- Intestinal lymphoma
- infertility
tx for Celiac disease
Strict gluten free diet
Causes of chronic abdominal pain
- constipation/encopresis
- Celiac disease
- IBD (Crohns, UC)
- Functional abdominal pain (IBS)
what are the 2 types of IBD and describe their similarities
Chron’s and ulcerative colitis
- Both are autoimmune disorders
- There can be some exam findings that will make you more suspicious for this diagnosis—anal tags or perianal fistulas
- Typically you will see changes in the CBC indicative of anemia and you will see elevated ESR and CRP
- Both diseases are diagnosed with endoscopy
- Both are treated with steroids, immune modulators, and nutrition;
- Both are periodically monitored by pediatric GI specialists
Who and WHAT does Crohn’s disease effect
- Affects preteens through adults
- 5 to 10 new cases per 100,000 individuals/year
- Affects any part of GI tract from mouth to anus
- PATCHY disease: most often effects terminal ileum, ileum and cecum and the colon
sx of Crohn’s Disease
- Abdominal pain (can wake from sleep)
- weight loss
- Diarrhea
- Hematochezia
- Growth failure
- Extraintestinal manifestations (like delayed puberty)
who and WHAT does Ulcerative colitis effect
- Affects preteens to adults (peak incidence 15-25 yo)
- 2.05-3.67/100, 000 per year in children
- Affects only the colon
- Diffuse, CONTINUOUS process starting at the rectum and extending more proximally into the colon
Active UC is characterized by
diffuse and continuous edema, erythema, friability, and ulceration
Sx of UC
- Abdominal pain
- weight loss
- fevers
- bloody, mucousy diarrhea
- nocturnal diarrhea
- Growth failure
- Extraintestinal manifestations (like delayed puberty
Definition of Functional abdominal pain (IBS)
MUST INCLUDE:
- Episodic or continuous abdominal pain
- No evidence of an inflammatory, anatomic, metabolic or neoplastic process that explains the subject’s sx
- Some loss of daily functioning
- Additional somatic symptoms such as headache, limb pain or difficulty sleeping
IBS cannot include what sx
- Persistent RUQ or RLQ pain
- dysphagia
- persistent vomiting
- GI blood loss
- nocturnal diarrhea
- family hx of IBD, celiac dz, or PUD
- pain that wakes the child from sleep
- arthritis
- perirectal disease
- involuntary weight loss
- deceleration of linear growth
- delayed puberty
- unexplained fever
who does IBS affect
Children school aged to adolescents
Features of IBS
- no discernible pattern
- nothing seems to consistently make it better or worse
- the child continues to grow and develop appropriately
what is IBS caused by
visceral hypersensitivity
IBS is a dx of exclusion. Before you can diagnose it, what screening labs must be normal?
Screening labs: CBC, CRP, ESR, TTG, IgA, CMP, GGT, and UA
tx of IBS
- Education: explain what condition the patient has
- Symptomatic:
- increased fiber and fluids;
- antispasmodics (Levsin subligual or Bentyl 10 mg QD-QID daily);
- can consider Tricyclic antidepressant—amitriptyline (10-20 mg daily);
- stress management and relaxation techniques
define nausea and regurgitation
Nausea - a sensation of impending emesis
Regurgitation - the return of small amounts of food or secretions to the hypopharynx -food is brought back to the mouth without abdominal and diaphragmatic muscular activity
*Emesis rarely occurs without nausea
define emesis and retching
Emesis (a.k.a. “vomiting”) - forceful expulsion of stomach contents through an open glottis
Retching (a.k.a. “dry heaves”) - same mechanism as vomiting but glottis remains closed
*Emesis rarely occurs without nausea
The approach to acute nausea and vomiting is based on three key questions:
- Is immediate therapy needed due to the consequences of nausea and vomiting regardless of the underlying cause?
- Are empiric treatment and reassurance sufficient?
- Is expeditious work-up required to establish the cause?- Is this a more serious problem, like an anatomical issue, that requires emergent intervention?
common causes of vomiting in neonates
- GERD
- Pyloric stenosis
- Necrotizing enterocolitis*
- Malrotation w/ volvulus
- Hirschsprung disease
- Atresias*, stenoses
- Metabolic disorders*
- Feeding intolerance
- unique to neonatal period
- Others, such as pyloric stenosis, Hirschsprung disease, and malrotation may be picked up outside of the neonatal period, typically in early infancy.
Common causes of vomiting in infants
- GERD*
- Gastroenteritis*
- Anatomic
- Intussusception
- Rumination
- Nutrient intolerances
- Overfeeeding
- Munchausen syndrome by proxy
*most common
Common causes of vomiting in childhood
- Gastroenteritis
- Infection
- Peptic ulcer/GERD
- Cyclic vomiting
- Psychogenic
- Toxic ingestion- should be considered in any child who has the motor skills to place objects in the mouth
- Intracranial mass
Common causes of vomiting in adolescene
- Gastroenteritis
- Peptic ulcer/GERD
- Psychogenic
- Intracranial mass
- Cyclic vomiting
- Bulimia
- Pregnancy
- Drugs of abuse
- Suicide attempt
*pschyogenic causes become more prominent
Bilious vomiting in the first months of life suggests
anatomical obstruction or other serious condition
With vomiting in neonates and infants it is important to:
- take it seriously
- Distinguish vomiting from regurgitation
- Bilious versus non-bilious
“For bilious vomiting, I give ____. It has never failed in the worst cases of persistent bilious vomiting. It can be repeated in half an hour if really necessary. The results are immediate.”
one teaspoonful of table salt
how to distinguish vomiting vs reguritation
Vomiting would likely be of larger volume and would certainly be forceful.
cause of bilious vomiting in older children
bilious vomiting can occur with any syndrome with repeated bouts of vomiting. As food is expelled, all that remains in the GI tract is saliva and bile
cause of bilious vomiting in neonatal or early infancy period
- malrotation with or without volvulus
- intussusception
what is a malrotation
- a developmental error in the formation of the G.I. tract in which the intestine does not complete its normal rotational pattern of fetal development
- incomplete rotation of the intestine during fetal development
Malrotation can cause symptoms of __ or __ and makes the intestine susceptible to volvulus.
incomplete or intermittent obstruction
what happens with volvulus
the large intestine wraps around a segment of the small intestine causing obstructive symptoms and ischemia.
-Volvulus can be intermittent and resolve spontaneously but can also be persistent and lead within hours to strangulation of the bowel.
how does malrotation present
- Usually presents in neonatal period with bilious emesis
- Infants and children may present with failure to thrive, signs of intermittent obstruction characterized by intermittent episodes of severe abdominal pain
- Malrotation can be missed in infancy and is occasionally not picked up until adolescence or later in life (25-50% of adolescents w/ malrotation are asymptomatic)
how do you diagnose malrotation
US or barium enema
tx of malrotation
surgical
how does malrotation with volvulus typically present
- severe abdominal pain,
- unremitting vomiting
- presents as an acute small bowel obstruction
*Life threatening surgical emergency
complications of malrotation with volvulus
- Significant bowel necrosis can result from compression of superior mesenteric artery
- high risk of short bowel syndrome
- Life threatening surgical emergency
what is intussusception
- Prolapse (telescoping) of one portion of bowel into adjacent segment, most commonly terminal ileum near the ileocecal junction
- Compression–> swelling-> obstruction
What is the presentation of intussusception
- neonate period: Most common at 3-12 months,
- 3:1 mal predominance
- abdominal pain
- vomiting (bilious or non-bilious)
- currant jelly stools (50%)
Dx and Tx of intussusception
barium enema or air enema: both are diagnostic AND therapeutic
prognosis of intussusception
Prognosis is strongly correlated with duration before reduction
-Complicated cases require surgical treatment
what is currant jelly stool
Mucus from the inflamed segment of intestine mixed with blood causes the currant jelly stool
*seen 50% of time w/ intussusception
Non-bilious vomiting causes
- intussusception
- GERD
- Pyloric stenosis
- acute appendicitis