Meckel Diverticulum

A 20 month old presents with abomdinal distention, irritability, abdominal distention, anorexia, and failure to thrive. On physical examination you noticing pruritic patches that seem to blister between their knees and ankles. What is their likely diagnosis?

Celiac disease

Name the term: Immune-mediated enteropathy triggered by the ingestion of gluten-containing grains (wheat, rye, barley). Is associated with HLA-DQ2 and HLA-DQ8

Celiac disease

What are three common causes of malabsorption diarrhea?

Celiac disease Cystic fibrosis Mycobacterial infection/whipple disease

Name there very common causes of infectious enterocolitis

Cholera Campylobcater Salmonellosis

What is the leading cause of death in children under five worldwide?

Diarrhea

What is the most common celiac associated cancer?

Enteropathy-associated T cell lymphoma

True or false: Hirschsprung disease always affects the duodenum

False, it always affects the rectum +/- the sigmoid colon

True or false: HNPCC is associated with pedunculate adenomas, but not in excessive numbers

False, it is associated with sessile serrated adenomas

True or false: UC, similar to Crohn's, is also transmural

False, it is not transmural. It involves the mucosa and submucosa

True or false: Osmotic diarrhea fails to resolve with fasting

False, it is relieved with fasting

What causes solitary rectal ulcer syndrome?

Impaired relaxation of the anorectal sphincter. Causes stool to sit in the same area, eventually eroding the mucosal layer causing ulceration

What are the four main categories of diarrhea?

Malabsorptive Osmotic Secretory Exudative

If a patient with UC has involvement through the entire colon, what would this be called?

Pancolitis

What is the most common cause of malabsorption diarrhea in the US?

Pancreatic insufficiency

Name the term: Multiple, sharply delineated areas of disease found in Crohn's patients.

Skip lesions

A patient presents with rectal bleeding, mucus discharge, and an inflammatory lesion on the anterior rectal wall. What is their likely diagnosis?

Solitary rectal ulcer syndrome

Areas of the intestines that are susceptible to ischemic bowel disease are known as the watershed zones, what anatomical areas does this include?

Splenic flexure, sigmoid colon and rectum

Name the term: Hydrolysis of carbs and peptides in the brush border of the mucosa of the small intestine

Terminal digestion

What are the most common sites for crohn's disease?

Terminal ileum, ileocecal valve, and cecum

True or false: Crohn disease may involve any area of the GI tract

True

A 32 year old women presents today with sudden onset of abdominal discomfort. She does use oral contraceptive use and occasionally smokes. What is a potential cause of her symptoms?

Venous obstruction, ischemic bowel disease

Name the obstruction: Twisting of the intestine

Volvulus

Does exudative diarrhea persist during fasting?

Yes

Where are diverticulum most common?

sigmoid colon

What is the age of onset for adult-onset celiac disease?

30 and 60 years

What is the most common appendiceal tumor?

Carcinoid at the tip

What percentage of individuals with Turcot Syndrome develop glioblastomas?

33%

Non-caseasting granulomas are in _____% of patients with Crohn's

35%

This is a frequent cause of hematocheezia. Malformed submucosal and mucosal blood vessels. Occurs most often in the cecum and ascending colon.

Angiodysplasia

What is the gold standard for diagnosing celiac disease?

Biopsy of the 2nd part of the duodenum

Name the term: Autosomal recessive mutation in lactase gene. Explosive diarrhea with water, frothy stool and abdominal distention after mild ingestion.

Congenital lactase deficiency

Venous obstruction is a common cause of ischemic bowel disease. What is an example of hyper coagulable states that may cause a venous obstruction leading to ischemic bowel.

Contraceptive use

What are the two forms of inflammatory bowel disease?

Crohn disease Ulcerative colitis

A child presents with pain, bloody stool and tenderness at the umbilicus. They do hav a small palpable mass near the umbilicus. What is the likely diagnosis?

Meckel diverticulum

Most common congenital abnormality of the small intestines

Meckel diverticulum

This congenital abnormality is caused by incomplete obliteration of the vitelline duct

Meckel diverticulum

Is transmural involvement likely in crohn's disease?

Yes

What percentage of individuals with UC have granulomas?

0%, granulomas are not present in UC

What is the usual age of onset of celiac disease?

6-24 months

What percentage of individuals with turbot syndrome develop medulloblastomas?

66%

Risk of adenocarcinoma increases ____-____ years after disease initiation

8-10

______% of intestinal obstructions are due to hernias, intestinal adhesions, intussusception, and volvo's.

80%

Name the term: Protrusion of a hernia sac (serosa-lined pouch of peritoneum) through a weakness or defect in the abdominal wall

Abdominal hernia

Name the term: Down-regulation of lactase gene expression

Acquired lactase deficiency

A patient presents with periumbilical pain that localizes to the RLQ. They have N/V, a low grade fever and an elevated WBC. What does this tell you?

Acute appendicitis

Name three major causes of ischemic bowel disease

Acute arterial obstruction Venous obstruction Hypo-perfusion

A patient presents with sudden, severe abdominal pain and tenderness. They have nausea, vomiting, and grossly melanic stool. On PE, decreased bowel sounds are noted in the lower left quadrant as well as a rigid abdomen. What is their likely diagnosis?

Acute transmural infarction

This is the most common neoplastic polyp

Adenoma

Name the obstruction: Intestinal tissue begins to grow together, when normally they would be separate.

Adhesions

Acute appendicitis is most common in what age groups?

Adolescents and young adults

What is the most specific serology for detecting celiac disease?

Anti-endomysial antibodies

What is the earliest lesion seen in an individual with Crohn's disease

Aphthous ulcer

If a patient with HNPCC develops colon cancer, what is the most common site of the colon?

Ascending colon.

A patient has recently been traveling to a water park. They are now presenting to you with explosive diarrhea and abdominal pain. What bug is likely causing their diarrhea?

Campylobacter spp.

What are the most common sites for intestinal angiodysplasia?

Cecum and ascending colon

What is the most common manifestation of malabsortpive diarrhea?

Chronic (>6 months) diarrhea

What is the most common malignancy of the GI tract? Second overall cancer behind lung cancer

Colonic adenocarcinoma

What are the two forms of lactase deficiency?

Congenital and acquired

How is intussusception diagnosed?

Contrast enemas

What are the two most important prognostic factors of an adenocarcinoma?

Depth of invasion Presence/absence of lymph node metastases

This skin condition is associated with celiac disease in the pediatric population. It is characterized by pruritic, blistering skin between knees and ankles.

Dermatitis herpetiformis

Name the term: Obstruction of the diverticula with stasis of contents that leads to inflammation.

Diverticulitis

Name the term: Painful, blood, small-volume diarrhea

Dysentery

External or internal: Dilation of the vessels of the inferior hemorrhoid plexus, located below the anorectal line.

External

True or false: Secretory diarrhea is resolved with fasting

False, it persists during fasting

True or false: Size has no correlation with risk of malignancy of adenoma polyps

False, size directly correlates wit risk of malignancy

True or false: Large bowel is the most commonly involved site for an intestinal obstruction due to stool collection in diverticular pouches

False, small bowel is most often involved due to a more narrow lumen

This is an autosomal dominant mutation in the APC gene. Patients will have 100-1000s of conventional adenomas. Colorectal adenocarcinoma develops in 100% of patients often before 30 if left untreated. What is the condition?

Familial Adenomatous Polyposis

How do invidiuals usually present if they have tumors in the proximal colon?

Fatigue and weakness due to iron-deficiency anemia

A patient has FAP+Osteomas of mandible, skull, and long bones + epidermal cysts + Desmoid and thyroid tumors + dental abnormalities. What is their likely condition?

Gardner syndrome

What are the two variants of FAP?

Garnder Syndrome Turcot Syndrome

It is possible to have gastric cells within a merkel diverticulum. What does this mean? What could this lead to?

Gastric cells can secrete acid which can lead to ulcers and bleeding

A patient with a history of smoking and ASCVD presents with post-prandial lower left abdominal pain. What imaging should you use to work up this patient?

Get a CT scan

A patient presents with anal pain, and bright red blood per rectum. What is the likely cause of their symptoms?

Hemorrhoids

Name the term: Dilated anal and perianal collateral vessels that connect the portal and caval venous system to relieve elevated venous pressure within the hemorrhoid plexus.

Hemorrhoids

A neonate presents with the failure to pass meconium after birth. What should you be concerned about?

Hirschsprung Disease AKA COngenital aganglionic megacolon

Also called congenital ganglionic megacolon

Hirschsprung disease

This disease is due to the lack of parasympathetic ganglion cells in submucosal and myenteric plexus of parts of the colon. This causes a functional obstruction with proximal dilation.

Hirschsprung disease

This is a common epithelial proliferation that carries no malignant potential. Most commonly found in the descending colon. Composed of mature goblet and absorptive cels, hyper plastic, stellate glands.

Hyperplastic polyps

What is the most sensitive serology for detecting celiac disease?

IgA antibodies to tissue transglutaminase or IgA/IgG antibodies to deaminated gliadin

What is the definition of diarrhea?

Increase in stool mass (>200 grams/day), frequency or fluidity

A patient being worked up for celiac disease recently had a biopsy taken. What would you expect to see in a positive biopsy for celiac disease?

Increased intraepithelial T-lymphocytes Crypt hyperplasia villous atrophy (loss of villi)

What is a transmural infarct?

Infarct of the entire wall

What is the most common cause of secretory diarrhea?

Infectious enterocolitis

A patient presents with diarrhea, abdominal pain, urgency, perianal discomfort, incontinence, and hemorrhage. What is their likely diagnosis?

Infectious enterocolitis (Secretory diarrhea)

What are the most common sites for acquired hernias?

Inguinal and femoral canals Umbilicus Prior surgical scars

What are the two phases of ischemic bowel disease?

Initial hypoxic injury and the reperfusion injury

Internal or External: Dilation of the vessels of the superior hemorrhoidal plexus, located within the distal rectum

Internal

Name the term: Breakdown of proteins, carbs, and fats into absorbable forms

Intraluminal digestion

Malabsorption is due to the disturbance in at least one of the four main phases of nutrient absorption. What are these four phases?

Intraluminal digestion Terminal digestion Transepithelial transport Lymphatic transport of absorbed lipids

Most common cause of intestinal obstruction in kids <2 years old

Intussusception

Name the obstruction: Occurs when a segment of the intestine constricted by a wave of peristalsis, telescopes into the non-constricted distal segment.

Intussusception

A patient is presenting with purulent, bloody stools. What is likely causing this? What type of diarrhea is this?

It is caused by an underlying inflammatory disease (Crohn's/UC or a severe infection) IT is exudative diarrhea

This is the most common type of hamartomatous polyp

Juvenile polyp

This is an autosomal dominant syndrome of up to 100 polyps. Increased risk of gastric, small bowel, colonic and pancreatic cancer.

Juvenile polyposis

What is an example of osmotic diarrhea?

Lactase deficiency

What is a mural infarction?

Loss of blood flow to the mucosa and submucosa

50-80% of acute appendicitis cases are associated with ___________________-

Luminal obstruction (fecalith)

Of the three classifications of adenomas, which is the most benign? Which is the worst?

Most benign is tubular Most risk for malignancy is villous

Where are sessile serrated adenomas more commonly found?

Most common in the ascending colon

What is the common colon cancer in HNPCC?

Mucinous adenocarcinoma

Define diverticulosis

Multiple diverticula

How do individuals usually present if they have tumors in the distal colon?

Occult bleeding, changes in bowel habits and LLQ cramping.

Name the term: Diarrhea that occurs with ingestion of substance that can't be absorbed.

Osmotic diarrhea

How is osmotic diarrhea distinguished from malabsorption diarrhea?

Osmotic diarrhea the stool content is at least 50 most more concentrated than plasma

What is an incarcerated hernia?

Permanent entrapment of the hernia

Name the disorder: Autosomal dominant disorder characterized by multiple GI hamartomatous polyps + mucocutaneoux pigmentation. Patients have an increased risk of colon, pancreatic, breast, lung, ovarian, uterine, and testicular cancer.

Peutz-Jeghers Syndrome

A patient has a small bowel obstruction caused by intussusception. The child is a year old. They also had a viral infection at the same time. Small masses of lymphatic tissue are found in the ileum, what are these patches called?

Peyer's patches

Name the term: Abdomen fills with mucin

Pseudomyxoma peritonei

Ulcerative colitis is limited to the _________ and __________

Rectum and Colon

A child presents with rectal bleeding. You suspect juvenile polyps, where would you expect these polyps to be located?

Rectum causing rectal bleeding

Of the two phases, which is associated with the greatest amount of damage?

Reperfusion injury

Name the term: This diarrhea is due to bacterial toxins, reduced absorptive surface area caused by disease or resection, secretagogues (laxatives), or medical problems that compromise regulation of intestinal function

Secretory diarrhea

What are the two morphologies of intestinal polyps?

Sessile Pedunculated

Name the Adenoma: Boot-shaped crypt base.

Sessile serrated adenomas

Acute arterial obstruction are potential causes of ischemic bowel disease. What are some causes of acute arterial obstruction?

Severe atherosclerosis Aortic aneurysm Embolization of cardiac vegetation or aortic atheroma

Hypoperfusion is a potential cause of ischemic bowel disease. What are three causes of hypo perfusion that may lead to ischemic bowel disease?

Shock, dehydration, vasoconstrictive drugs

Name the term: Excessive fecal fat and frothy, greasy, yellow or clay-colored stool

Steatorrhea

Meckel diverticulum may contain cells from both the ___________ and ____________

Stomach and pancreas

In addition to watershed zones, what other general areas are poorly perfused, putting them at risk of ischemic bowel disease?

Surface epithelium

Susceptible areas for ischemic bowel disease include the watershed zones, what does this mean?

They are the end of the arterial supply, last to get blood.

A patient presents with severe abdominal pain and distention, they have been vomiting and have been constipated. On examination of the vomit, you notice that there are scant amounts of feces. What does this tell you?

They likely have an intestinal obstruction

Name the term: Transport of nutrients, fluid and electrolytes across the brush border.

Transepithelial transport

What are the three classifications for adenoma's (cancerous polyps)

Tubular Tubulovillous Villous

If 80% of intestinal obstructions are due to hernias, intestinal adhesions, intussception and volvulus, what is the other 20% due to?

Tumors and infarcts

A patient has FAP + CNS tumors. What is their likely diagnosis?

Turcot syndrome

This is a rare chronic disease characterized by malabsorption, lymphadenopathy, and arthritis due to Tropheryma whippelii which is a gram positive actinomycete.

Whipple disease

You suspect your patient has malabsorption diarrhea. To help confirm this, you have them fast, should their diarrhea resolve with fasting?

Yes it should

Are sessile serrated adenomas more likely to have malignant potential than pedunculate?

Yes, they are more likely malignant

This is also called lynch syndrome, it is a germane mutation in mismatch repair genes. Mutation in MSH2 or MLH1. They ultimately get cancer at severe sites including: Colorectal, endometrial, gastric, ovarian, urothelial, brain, hepatobiliary and skin. What is their likely syndrome?

hereditary nonpolyposis colorectal cancer

What is a strangulated hernia?

incarcerated hernia with resulting ischemia, will result in signs and symptoms of ischemia and intestinal obstruction or bowel necrosis