Intestinal Disorders B&B Flashcards
what is the typical cause of appendicitis in adults vs children?
adults - fecaliths (hard fecal masses) obstructing opening to cecum
children - lymphoid hyperplasia obstructs opening to cecum
what is the classic clinical presentation of appendicitis?
abdominal pain begins mid-epigastric due to visceral peritoneum inflammation - not well localized
as inflammation progresses, pain moves to RLQ due to parietal peritoneum inflammation - can be localized
classic location = McBurney’s Point: 1/3 distance from the iliac crest to the umbilicus (RLQ)
also presents with fever and nausea
what is the significance of McBurney’s Point
classic location of appendicitis pain - 1/3 distance from the iliac crest to the umbilicus (RLQ)
Pt is 48yo M presenting w/ fever, nausea, and abdominal pain that began around the stomach and has now moved to the RLQ - what are you concerned about?
appendicitis: abdominal pain begins mid-epigastric due to visceral peritoneum inflammation (not well localized), then moves to RLQ due to parietal peritoneum inflammation (better localized)
classically ends up in McBurney’s Point - 1/3 distance from the iliac crest to the umbilicus (RLQ)
what is meant by “rebound tenderness,” and which 3 causes of this require urgent surgical intervention?
“rebound tenderness” = pain on release after pressing abdomen, reflects peritoneal inflammation
require urgent surgical intervention (”acute abdomen”):
1. appendicitis
2. diverticulitis
3. ectopic pregnancy
acute abdomen can progress to perforation of abdominal viscus!
what causes the weakness in the muscularis mucosa that allows diverticulum to form?
diverticulum = blind pouch/sac extending out from GI tract, containing mucosa + submucosa, due to breakdown of muscualris mucosa
occur where the vasa recta penetrate the muscularis mucosa, because these are areas of weakness
[technically these are “false diverticulums” because they lack muscular layer]
what is the typical cause of diverticulosis, and where does this typically occur anatomically?
caused by straining to pass stool, which creates wall stress - risk factors include low fiber diet (—> hard stools)
diverticulosis = many diverticula in GI tract, usually in sigmoid colon
[recall diverticulum = blind pouch/sac extending out from GI tract, containing mucosa + submucosa, due to breakdown of muscualris mucosa]
hematochezia =
lower GI bleeding
what are the presenting symptoms of diverticulitis?
diverticulum = blind pouch/sac extending out from GI tract, containing mucosa + submucosa, due to breakdown of muscualris mucosa
diverticulosis (multiple diverticula in GI tract) is usually asymptomatic, but may cause symptoms if extensive inflammation occurs —> diverticulitis
presents w/ fever + elevated WBC + LLQ pain (“left-sided appendicitis”) because diverticula occur in sigmoid colon + “occult blood” in stool (can’t see but can measure in labs)
Pt is a 45yo F presenting w/ fever and LLQ pain. Labs show elevated WBC and occult blood. What are you concerned about?
diverticulum = blind pouch/sac extending out from GI tract, containing mucosa + submucosa, due to breakdown of muscualris mucosa
diverticulosis (multiple diverticula in GI tract) is usually asymptomatic, but may cause symptoms if extensive inflammation occurs —> diverticulitis
presents w/ fever + elevated WBC + LLQ pain (“left-sided appendicitis”) because diverticula occur in sigmoid colon + “occult blood” in stool (can’t see but can measure in labs)
of what is colovesical fistula a complication?
colovesical fistula = fistula of GI diverticulus to bladder —> pneumaturia (air in bladder), fecaluria (fecal in urine), dysuria
diverticulum = blind pouch/sac extending out from GI tract, containing mucosa + submucosa, due to breakdown of muscualris mucosa
most common cause of small bowel obstruction
adhesions - bands of scar tissue in peritoneal cavity formed after surgery
what is intussusception, and how does it present? include where it occurs
intussusception: “telescoping” of intestine as it folds into its own lumen —> causes backup of intestinal content
blocks bloods supply, causing necrosis —> ”currant jelly” GI bleeding
rare in adults, common in children (<1 yo), often near ileocecal junction
medical emergency !
what are the causes of lead points for intussusception in children (2) vs adults (1)?
intussusception: “telescoping” of intestine as it folds into its own lumen (at “lead point”) —> causes backup of intestinal content + “currant jelly” GI bleeding (necrosis)
children (<1): Meckel’s diverticulum or lymphoid hyperplasia of Peyer’s patches, strongly associated with adenovirus gastroenteritis
adults (rare): tumors
which virus has a strong association with intussusception in children?
intussusception: “telescoping” of intestine as it folds into its own lumen (at “lead point”) —> causes backup of intestinal content + “currant jelly” GI bleeding (necrosis)
strongly associated w/ adenovirus gastroenteritis in children (<1) causing lymphoid hyperplasia of Payer’s patches
where does volvulus typically occur (2)?
volvulus = twisting of bowel around mesentery —> obstruction/ infarction
classically occurs at sigmoid colon or cecum
occurs mostly in elderly (~70yo) or secondary to Meckel’s diverticulum in children
what are the 2 classic imaging findings of volvulus when it occurs at the sigmoid colon?
volvulus = twisting of bowel around mesentery —> obstruction/ infarction
classic sigmoid findings = dilated sigmoid colon + airless rectum
occurs mostly in elderly (~70yo) or secondary to Meckel’s diverticulum in children
what are the common causes of small bowel obstruction (SBO) (3) vs large bowel obstruction (LBO) (3)?
SBO: Adhesion, Bulge (hernia), Cancer [ABC]
LBO: Tumor, Adhesions, Volvulus [TAV]
[volvulus = twisting of bowel around mesentery
what is the cause of Hirschsprung’s Disease?
failure of neural crest cell migration —> absent ganglion cells in Meissner’s plexus (submucosa) and Auerbach’s plexus (muscularis)
result is failure of peristalsis and subsequent obstruction
associated with Down Syndrome
with what genetic disorder is Hirschsprung’s Disease associated?
failure of neural crest cell migration —> absent ganglion cells in Meissner’s plexus (submucosa) and Auerbach’s plexus (muscularis)
result is failure of peristalsis and subsequent obstruction
associated with Down Syndrome
what is the initial presentation of Hirschsprung’s Disease?
failure of neural crest cell migration —> absent GI ganglion cells (Meissner’s, Auerbach’s plexus)
failure of peristalsis —> dilated bowel behind obstruction and failure to pass meconium (first stool) + abdominal distention, bilious vomiting + no stool in rectal vault
associated with Down Syndrome
how is Hirschsprung’s Disease diagnosed on imaging and biopsy?
failure of neural crest cell migration —> absent GI ganglion cells —> failure of peristalsis and subsequent obstruction
barium imaging shows cone-shaped ”transition zone” where bowel becomes small
rectal “suction” biopsy shows absence of ganglion cells - this works because the rectum is ALWAYS involved
what are common causes of ileus (2)?
ileus = loss of bowel peristalsis, can cause N/V, constipation, obstipation (cannot pass stool)
common causes include narcotics and post-operative (due to anesthesia)
ogilvie syndrome
“pseudo-obstruction” of intestines - dilated colon in absence of lesion
usually in hospitalized or nursing home setting in patients w/ severe illness or recent surgery, often associated with narcotics
just think of it as body is so sedentary, the bowel became sedentary, too
