ICL 13.4: Disorders of the Small Intestine Flashcards
glossitis
plummer vincent
multiple ulcers in the GI tract, diarrhea, increased gastric acidity, high gastrin levels
zollinger-elefson
immunosuppressed patient with ulcers in the esophagus
CMV = ulcers
candida is a dirty, grey membrane, not ulcers
11/18 translocation
MALT lymphoma
Kukenburg tumor
ovarian mets from gastric cancer
Kirchow node
left supraclavicular lymph nodes
enlarged in gastric cancer
Barrett esophagus
squamous to columnar metaplasia
premalignant condition in the stomach
atrophic gastritis
protein losing gastropathy
Meinitrier disease
trichoboazar
hair balls
produces urease
H. pylori
tinitis plastica
involves entire thickness of the wall; it’s infiltrating
63 year old chronic alcoholic with massive hemetemesis
esophageal varices
they happen due to portal hypertension
signet ring cells
diffuse gastric cancer; gastric type
what are the congenital anomalies of the small intestine?
- heteroptopia
- atresia and stenosis
- Meckel diverticulum
what is heteroptopia?
usually pancreas, but can be gastric mucosa appearing as small nodules in the mucosa or intestinal wall
what is atresia and stenosis?
duodenal atresia is most common, followed by jejunum and ileum
stenosis can also be acquired e.g. intussusceptions
what is Meckel diverticulum?
failure of the vitelline duct (connects the developing gut to the yolk sac) to involute
found on the anti-mesenteric side of gut within two feet of ileocecal valve
contains all three layers of normal bowel wall = true diverticulum!!
heterotopic rests of gastric or pancreatic tissue found in 50% –> peptic ulceration –> bleeding
what are the complications of Meckel diverticulum?
- intussusception
- incarceration
- perforation
most are incidental findings
what is diarrhea?
an increase in stool mass, frequency or fluidity in most patients
characterized by pain, urgency, perianal discomfort and incontinence
what is dysentery?
low-volume, painful, bloody diarrhea
what is secretory diarrhea? what bugs can cause it?
passage of >500 ml/day of watery stools, isotonic with plasma
ex. rotavirus, E. coli, V. cholaerae, villous adenomas and excessive laxative use
what is osmotic diarrhea? what causes it?
pssage of > 500 ml/day of stools, osmolality exceeds that of plasma by > 50 mOsm
ex. lactase deficiency and antacids
what are exudative diseases? what bugs cause it?
the passage of frequent purulent, bloody stools
ex. Shigella, Salmonella
what is malabsorption? what conditions cause it?
bulky stools with excess fat that floats on the water (steatorrhea) and increased osmolality
ex. Celiac Sprue and Crohn disease
what is deranged motility? what causes it?
improper gut neuromuscular function causes variable patterns of increased stool volume
ex. surgical reduction of bowel length, diverticula
what is infectious enterocolitis?
intestinal diseases of microbial origin
characterized by diarrhea and in some instances ulceration of the bowel
causes >12,000 deaths per day among children in developing countries and equals ½ of all deaths before age 5 worldwide
a 7 year old boy present with watery diarrhea for 3 days. He reports that two if his best friends at school have the problem.
diagnosis?
viral infection! probably norwalk virus
watery diarrhea = infection = cholera or viral infection –> cholera is really more of a 3rd world country disease so this kid doesn’t have it
which viruses can cause infectious enterocolitis?
- rotaviruses (infants)*
- norwalk virus*
school aged children; sometimes adults –> Norwalk virus is responsible for the majority of cases of nonbacterial food-borne epidemic gastroenteritis in all age groups
- adenovirus (infants)
- astroviruses (children)
after an office potluck 5 members of the staff start vomiting and have diarrhea 3 hours after lunch where they ate egg and chicken salads.
diagnosis?
food poisoning caused by staph aureus!!
staph has really fast onset infections due to preformed toxins; salmonella and shigella take 3-4 days before symptoms present
which bugs can cause food poisoning?
BACTERIA
1. e. coli (food borne; invasive & non-invasive forms)
- vibrio cholerae (water borne; enterotoxin –> secretory diarrhea)
- S. aureus* (food poisoning; preformed toxin)
- salmonella and shigella (invasive bloody diarrhea; toxins)
- typhoid fever
- MAI (AIDs associated)
- clostridium difficile (antibiotic associated colitis)
PARASITES
1. giardia lamblia* –> malabsorption; steatorrhea
- entamoeba histolytica* –> bloody diarrhea; dysentery
what is the clinical presentation of a c. diff infection?
65 year old woman comes in with bloating and severe purulent diarrhea and a week ago she was hospitalized for pneumonai
she has pseudomembranous colitis caused by antibiotics!
a 25 year old medical student presents with steatorrhea and abdominal pain 3 weeks after his return from spring break where he vacationed with his friends I the Grand Cayman.
diagnosis?
Tests:
giardia
steatorrhea = malabsorption
how is AIDS associated with diarrhea?
there is diarrheal illness in 50% of AIDS patients in developed countries
some malbsorption, some ulcerative colitis, infections with other organisms; possibly due to HIV mucosal damage, itself
how are transplants associated with transplants?
bone marrow transplants have high rates of diarrhea due to graft vs. host reaction
what miscellaneous things can cause diarrhea?
- drugs
- radiation
- neutropenic colitis
what is malabsorption?
characterized by suboptimal absorption of fats, fat-soluble and other vitamins, proteins, carbohydrates, electrolytes and minerals, and water
what is the pathogenesis of malabsorption? what conditions are associated with each cause?
- defective intraluminal digestion
ex. pancreatic insufficiency, Zollinger-Ellison syndrome, bacterial overgrowth - primary mucosal cell abnormalities
ex. defective terminal digestion (lactose intolerance*), defective epithelial transport (abetalipproteinemia) - reduced small intestinal surface area
ex. Chrohn disease, celiac sprue - lymphatic obstruction
ex. TB, lymphoma - infections
ex. Whipple disease*, tropical sprue - iatrogenic
ex. gastrectomy, distal ileal resection
what is the clinical presentation of malabsorption?
- chronic diarrhea and steatorrhea = bulky, frothy, greasy, foul smelling stools
- weight loss
- anorexia
- abdominal pain
if multiple systems are involved and it’s prolonged, it can lead to these symptoms due to vitamin deficiencies:
- anemia
- petechiae
- hemorrhages
- dermatitis
- bone pain
- peripheral neuropathy
- latent tetany
- menstrual and reproductive disturbances
in the USA, US pancreatic insufficiency, Celiac Sprue and Crohn disease are most important
a 60 year old male presents with bloating, diarrhea and arthralgias for six months.
PE: Hyperpigmented patches of his hands and neck
mini mental exam reveals some confusion
diagnosis?
tests?
Whipple disease
joint, skin, neuro problems
what is whipple disease?
a rare systemic disease of primarily the intestines, joints, and CNS
caused by gram-positive actinomycete, Tropheryma whippelii
pathogenesis unknown
patients are usually white, M:F = 10:1, 40-50 years of age
once neuro manifestations have happened, you can reverse everything else except the neuro symptoms
how do you diagnose whipple disease?
lamina propria is laden with distended macrophages, containing tiny rod-shaped bacilli that are PAS positive!!!!
what is the clinical presentation of whipple disease?
- malabsorption syndrome
- anthropathy is often the initial presentation = joint disease
- lymphadenopathy
- hyperpigmentation
- polyarthritis
- cardiac and neurologic signs
responds to broad spectrum antibiotics
a 40 year old African American lady present with a chronic complaint of bloating and excessive gas especially after she eats pizza at the weekly bingo evening at her church
diagnosis?
pathogenesis?
disaccharidase (lactase) deficiency
african america, bloating, pizza
what is lactase?
disaccharidase is an apical membrane enzyme that cleaves lactose
if you don’t have lactase, lactose builds in the gut lumen which leads to osmotic purgative effective causing osmotic diarrhea and malabsorption!
what is the pathogenesis of lactase deficiency?
incomplete breakdown of disaccharide (lactose) into glucose and galactose leads to osmotic diarrhea
bacterial fermentation of unabsorbed sugar leads to increased hydrogen production and gaseous symptoms
what are the 2 forms of lactase deficiency?
- congenital form
2. acquired form
what is the congenital form of lactase deficiency?
presents in infants on exposure to milk or milk products
explosive, watery diarrhea and abdominal distension that stops when taken off milk
what is the acquired form of lactase deficiency?
more common
adults, blacks and Native Americans > whites; sometimes related to viral or bacterial enteric infection
75 year old hypertensive, hyperlipidemic diabetic patient prestns with sever diffuse abdominal pain and bloody diarrhea for 2 days.
PE: tenderness and guarding lower abdomen
diagnosis?
ischemic bowel disease
he has atherosclerosis of blood vessels that led to ischemia
bloody diarrhea from infarcted intestine
what is ischemic bowel disease?
can be restricted to either the small or large intestine, or both
infarctions seen with acute occlusion of celiac, superior and inferior mesenteric arteries
insidious loss of one vessel may go unnoticed due to rich anastomoses
what are the causes of ischemic bowel disease?
- arterial thrombosis
- arterial embolism
- venous thrombosis
- nonocclusive ischemia; e.g. cardiac failure, shock, etc.
- radiation injury
- volvulus
- stricture
what are the types of lesions you can see in ischemic bowel disease?
- transmural infarction
- mural and mucosal infarction
- chronic ischemia
what are transmural infarction in ischemic bowel disease?
all layers due to sudden occlusion of major vessels
bowel is swollen, gangrenous and perforates in few days
what are mural and mucosal infarctions in ischemic bowel disease?
most commonly due to hypoperfusion in watershed areas
necrosis of mucosa only; mucosa hemorrhagic; serosa normal
what is chronic ischemia in ischemic bowel disease?
mucosal atrophy; ulcerations; mural fibrosis
can lead to stricture
what are the clinical features of ischemic bowel disease?
short time between symptoms and perforation so if you think they have ischemia you have to act quickly!!
TRANSMURAL INFARCTS
1. sudden severe abdominal pain and tenderness; sometimes nausea, vomiting and bloody diarrhea or melena
- shock and vascular collapse in hours
- peristalsis is diminished
MUCOSAL/MURAL INFARCT
1. may not be fatal if cause corrected
- nonspecific abdominal complaints and intermittent bloody diarrhea, but may progress to extensive infarction & sepsis
CHRONIC ISCHEMIA
insidious with intermittent bloody diarrhea, resembling inflammatory bowel disease
PAS positive rods
whipple disease
osmotic diarrhea
lactose intolerance
bloody painful low volume diarrhea
desentery
infection with entamoeba
rotavirus
infant diarrhea
giardia
malabsorption
norwalk virus
school aged kid diarrhea
16 year old African American high school junior presents with bloating, excessive gas 4 hours after enjoying ice cream and cake at her best friend birthday party.
diagnosis?
lactase deficiency
bloating and gas because the bacteria is fermenting the lactose that isn’t being cleaved into glucose
56 year old male presents with mental confusion for six months and hyperpigmentation of his hands he also reports foul smelling diarrhea.
diagnosis?
whipple disease
due to T. whippelii PAS gram + rods in macrophages in the lamina propria of the intestine
Mom brings in her 3 month old infant as she has noticed watery diarrhea for the last 3 days he goes to a baby sitter who takes care of five other infants.
daignosis?
rotavirus
