Pathology Year 2: Inflammatory Bowel Diseases

Questions and Answers

What is primarily responsible for diverticular disease in adults over 60 years old?

High fiber diet

Sedentary lifestyle

Wall stress due to low fiber diet (correct)

Genetic predisposition

Which systemic manifestation is NOT typically associated with ulcerative colitis?

Ankylosing spondylitis

Primary sclerosing cholangitis

Asthma (correct)

Erythema nodosum

Which complication is most commonly associated with diverticulitis?

Intussusception

Adhesions

Perforation (correct)

Herniation

What is a common clinical feature of diverticular disease?

Cramping or lower abdominal pain Signup and view all the answers

What anatomical feature is a primary site for the formation of diverticula?

Sigmoid colon Signup and view all the answers

Which of the following is NOT a type of mechanical intestinal obstruction?

Strangulation Signup and view all the answers

What dietary change is recommended to potentially prevent progression of diverticular disease?

High fiber diet Signup and view all the answers

Which condition is characterized by inappropriate communication between the intestine and adjacent organs?

Fistula Signup and view all the answers

What is the primary blood supply to the caecum and ascending colon?

Superior mesenteric artery Signup and view all the answers

Which cellular component is primarily responsible for the antimicrobial properties in the caecum and ascending colon?

Paneth cells Signup and view all the answers

What is the hallmark feature of Hirschsprung's disease?

Absence of ganglion cells in the bowel wall Signup and view all the answers

Which of the following is NOT a clinical feature of Hirschsprung's disease?

Diarrhea in newborns Signup and view all the answers

Which form of intestinal infarction affects all layers of the intestinal wall?

Transmural infarction Signup and view all the answers

What condition is characterized as a functional obstruction due to the absence of enteric ganglia?

Hirschsprung's disease Signup and view all the answers

In the comparison of Crohn's disease and ulcerative colitis, which statement is true?

Crohn's disease often leads to fistula formation. Signup and view all the answers

Which of the following conditions is a type of colitis characterized by inflammation of specific segments of the bowel?

Ulcerative colitis Signup and view all the answers

What is a common complication associated with proximal innervated colon in patients with Hirschsprung's disease?

Perforation of megacolon Signup and view all the answers

What type of adhesive tissue formation can disrupt normal bowel movement and cause pain?

Adhesions Signup and view all the answers

What is the primary factor predisposing individuals to hemorrhoids?

Portal hypertension Signup and view all the answers

Which clinical feature is unique to Crohn’s disease compared to ulcerative colitis?

Presence of skip lesions Signup and view all the answers

What is the main pathological feature that differentiates ulcerative colitis from Crohn’s disease?

Mucosal and submucosal inflammation only Signup and view all the answers

What is a common complication associated with chronic ulcerative colitis?

Toxic megacolon Signup and view all the answers

Which of the following is NOT a characteristic of Crohn’s disease?

Continuous lesions Signup and view all the answers

In terms of demographic prevalence, which group is most at risk for developing inflammatory bowel disease?

Caucasians and Ashkenazi Jews Signup and view all the answers

Which type of exudate characterizes antibiotic-associated colitis?

Pseudomembrane Signup and view all the answers

What is a primary clinical symptom of necrotising enterocolitis in neonates?

Signs of gastrointestinal bleeding Signup and view all the answers

What is often considered a risk factor for the development of diverticular disease?

Low fiber intake Signup and view all the answers

Which type of bowel involvement is typically seen in Crohn’s disease?

Transmural inflammation Signup and view all the answers

What diagnostic method is most commonly used to identify ulcerative colitis?

Colonoscopy Signup and view all the answers

What is a potential systemic manifestation of Crohn’s disease?

Migratory polyarthritis Signup and view all the answers

Which of the following does NOT typically present with abdominal pain and bloody diarrhea?

Hemorrhoids Signup and view all the answers

What is the significance of detecting cytotoxin in stool for antibiotic-associated colitis?

It confirms the presence of Clostridium difficile. Signup and view all the answers

Which of the following regions are part of the large intestine? (Select all that apply)

Caecum Signup and view all the answers

Which artery supplies the caecum to the splenic flexure?

Superior mesenteric Signup and view all the answers

Which artery supplies the remainder of the colon to the rectum?

Inferior mesenteric artery Signup and view all the answers

Which of the following supplies the lower portion of the rectum?

Haemorrhoidal branches Signup and view all the answers

Which of the following statements is true regarding the histology of the large intestine's mucosa?

Has crypts and surface epithelium but no villi Signup and view all the answers

Which of the following statements about the mucosa layers of the large intestine are correct? (Select all that apply)

Lamina propria Signup and view all the answers

What is the structure of the submucosa found in the large intestine?

Loose connective tissue with a plexus of Meissner Signup and view all the answers

What are the components of the muscularis propria in the large intestine?

Inner circular layer, outer longitudinal layer, and myenteric plexus of Auerbach Signup and view all the answers

What type of tissue is found in the serosa of the large intestine?

Mesothelial cells and fibrous tissue Signup and view all the answers

Which type of mucosal cell is known for producing antimicrobial properties and immune mediators?

Paneth cells Signup and view all the answers

Where are Paneth cells located in the human body?

Caecum and ascending colon Signup and view all the answers

Which of the following statements about endocrine cells and their products in the digestive system is correct?

Endocrine cells secrete hormones that directly modulate digestive functions. Signup and view all the answers

Which of the following statements about goblet cells in the large intestine is true?

Goblet cells secrete mucus to lubricate the intestinal contents. Signup and view all the answers

Which of the following statements about Hirschsprung's disease is true?

It frequently involves the rectum and sigmoid colon. Signup and view all the answers

What is the primary mechanism involved in the pathogenesis of Hirschsprung's disease?

Arrested migration of neural crest cells into the bowel wall Signup and view all the answers

Where is Auerbach's plexus located?

Between the circular and longitudinal muscle layers of the intestine Signup and view all the answers

Where is Meissner's plexus located?

Submucosa Signup and view all the answers

What is the primary characteristic of Hirschsprung's disease?

Presence of an aganglionic segment in the rectum Signup and view all the answers

What does an aganglionic (aperistaltic) narrow segment in the rectum cause?

Functional obstruction, with dilatation of the unaffected proximal colon (megacolon) Signup and view all the answers

Which of the following are clinical features of Hirschsprung's disease? (Select all that apply)

Failure to pass meconium Signup and view all the answers

In Hirschsprung's disease, what percentage of sporadic cases have mutations in the RET gene?

15% Signup and view all the answers

In sporadic cases of Hirschsprung's disease, mutations occur in which gene?

RET gene Signup and view all the answers

Which of the following statements about ischemic bowel disease is correct? (Select all that apply)

It may affect both small and large intestines. Signup and view all the answers

What type of bowel infarction occurs due to sudden occlusion (thrombosis/embolism) of a major vessel?

Transmural infarction Signup and view all the answers

Mural infarction refers to necrosis of which layers of the gastrointestinal tract?

The mucosa & submucosa Signup and view all the answers

Mucosal infarction is defined as necrosis of the:

mucosa only Signup and view all the answers

Which of the following are characteristics of chronic ischemic bowel disease? (Select all that apply)

Inflammation Signup and view all the answers

Mural/mucosal infarction due to hypoperfusion occurs primarily in which of the following?

Watershed areas Signup and view all the answers

Which of the following mechanisms are involved in the pathogenesis of ischaemic bowel disease? (Select all that apply)

Arterial occlusion Signup and view all the answers

What are some contributing factors to non-occlusive ischaemia in bowel disease? (Select all that apply)

Heart failure Signup and view all the answers

Which of the following are clinical features of ischaemic bowel disease? (Select all that apply)

Older individuals Signup and view all the answers

A 75-year-old male with a history of atrial fibrillation presents with sudden-onset severe abdominal pain and bloody diarrhea. What is the most likely diagnosis in this patient?

Transmural Infarction of the Bowel Signup and view all the answers

Case-Based MCQ on Mucosal and Mural Infarction

A 60-year-old female with a history of congestive heart failure presents to the clinic with intermittent abdominal pain and episodes of bloody diarrhea over the past week. She describes the pain as crampy and notes that it often worsens after meals. On physical examination, there are no signs of peritoneal irritation, and bowel sounds are present. Basic lab results are unremarkable, and imaging studies show no evidence of bowel perforation or complete obstruction. The patient’s symptoms improve with conservative management, including intravenous fluids and bowel rest.

What is the most likely diagnosis in this patient?

Mucosal and Mural Infarction Signup and view all the answers

Which of the following statements about Chronic Ischemic Colitis is true?

It often presents with intermittent bloody diarrhoea. Signup and view all the answers

What is angiodysplasia characterized by?

Tortuous dilatations of blood vessels in the caecum and right colon Signup and view all the answers

In which part of the gastrointestinal tract is ANGIODYSPLASIA commonly found?

Caecum and right colon Signup and view all the answers

What is angiodysplasia characterized by?

Acquired malformed vessels in the mucosa and submucosa Signup and view all the answers

Which of the following conditions is associated with angiodysplasia? (Select all that apply)

Aortic stenosis Signup and view all the answers

Which of the following is associated with Hereditary Hemorrhagic Telangiectasia?

Telangiectasia Signup and view all the answers

What is true about Telangiectasia?

It may rupture and cause bleeding. Signup and view all the answers

What are hemorrhoids primarily characterized by?

Variceal dilatation of submucosal venous plexi around the anus and lower rectum Signup and view all the answers

Where do haemorrhoids typically occur due to increased pressure in the veins?

Rectal area Signup and view all the answers

Which of the following are common predisposing factors for haemorrhoids? (Select all that apply)

Constipation Signup and view all the answers

HAEMORRHOIDS can be classified as which of the following? (Select all that apply)

Internal (inside the anus) Signup and view all the answers

Which of the following are clinical features of haemorrhoids? (Select all that apply)

Bright red stool Signup and view all the answers

Which of the following statements about necrotising enterocolitis (NEC) is true?

NEC is an acute necrotising inflammation of the small and large bowel. Signup and view all the answers

Which of the following best describes the condition characterized by a combination of ischaemia, colonization by pathogenic organisms, excess protein in the lumen, and functional immaturity of the gut?

Necrotising enterocolitis Signup and view all the answers

What is a common characteristic of necrotising enterocolitis (NEC) in infants?

Occurs typically between day 2-4 of life Signup and view all the answers

What characterizes antibiotic-associated colitis (pseudomembranous colitis)?

Acute colitis with an adherent inflammatory exudate Signup and view all the answers

Antibiotic-associated colitis pseudomembrane is composed of which of the following?

Mucus, fibrin & inflammatory debris Signup and view all the answers

What is the main cause of antibiotic-associated colitis?

Clostridium difficile infection Signup and view all the answers

What is a key component of the clinical presentation for antibiotic-associated colitis?

Diarrhea Signup and view all the answers

What is a key diagnostic method for antibiotic-associated colitis?

Detection of cytotoxin in stool Signup and view all the answers

Which of the following are classified as idiopathic inflammatory bowel diseases? (Select all that apply)

Crohn’s disease Signup and view all the answers

What is the most common form of idiopathic inflammatory bowel disease among Caucasian and Ashkenazi Jews?

Crohn's Disease Signup and view all the answers

Which statement about idiopathic inflammatory bowel disease is correct?

Most frequently present in the teens and early 20s but can develop at any age Signup and view all the answers

Which of the following statements correctly describes the pathogenesis of idiopathic inflammatory bowel diseases (IBD) regarding mucosal immunity and genetic polymorphism?

Genetic polymorphisms related to anti-inflammatory factors, such as IL-10, play a role in the pathogenesis of IBD. Signup and view all the answers

Which of the following statements about Crohn's disease are correct? (Select all that apply)

It can affect any portion of the gastrointestinal tract Signup and view all the answers

Which of the following findings is associated with Crohn's disease?

Creeping fat Signup and view all the answers

Aphthous mucosal ulcers that coalesce into long, linear serpentine ulcers along the bowel axis can be associated with which of the following?

Crohn's Disease Signup and view all the answers

Linear ulcers with edema of the intervening mucosa seen in Crohn's Disease can be called a:

Cobblestone appearance Signup and view all the answers

Which of the following are specific microscopic features of Crohn's disease? (Select all that apply)

Inflammation is Transmural Signup and view all the answers

Which of the following are clinical features of Crohn's disease? (Select all that apply)

Malabsorption Signup and view all the answers

Which of the following is a common diagnostic procedure for Crohn's disease?

Small bowel or colon biopsy Signup and view all the answers

Which of the following are complications associated with Crohn's disease? (Select all that apply)

Obstruction Signup and view all the answers

In Crohn's disease, obstruction secondary to transmural fibrosis/stricture primarily occurs in which part of the digestive system?

Terminal ileum Signup and view all the answers

Which of the following are systemic manifestations of Crohn's disease? (Select all that apply)

Arthritis Signup and view all the answers

In Ulcerative Colitis (UC), where does the gross pathology usually begin and how does it extend?

Begins in the rectum and extends continuously proximally Signup and view all the answers

Which of the following statements is true regarding the gross pathology of ulcerative colitis?

Involves the entire colon (pancolitis), without skip areas Signup and view all the answers

Which of the following microscopic features are characteristic of ulcerative colitis (UC) inflammation confined to the mucosa and submucosa? (Select all that apply)

Cryptitis and crypt abscesses Signup and view all the answers

Which of the following are clinical features of Ulcerative Colitis (UC)? (Select all that apply)

Intermittent attacks of bloody mucoid diarrhoea Signup and view all the answers

COLITIS-ASSOCIATED NEOPLASIA risk is related to which of the following factors? (Select all that apply)

Duration Signup and view all the answers

Which of the following are known complications of Ulcerative Colitis (UC)? (Select all that apply)

Toxic megacolon Signup and view all the answers

What is the cause of toxic megacolon in ulcerative colitis?

Toxic damage to muscularis propria and neural plexus with shutdown of neuromuscular function Signup and view all the answers

Which of the following are systemic manifestations of Ulcerative Colitis? (Select all that apply)

Erythema nodosum Signup and view all the answers

What is diverticular disease?

A condition characterized by blind pouches leading off the alimentary tract communicating with the lumen Signup and view all the answers

In the colon, which of the following statements about diverticular disease is true?

There are defects in the muscle wall where nerves and vessels penetrate. Signup and view all the answers

What leads to the formation of diverticula in the colon?

Vasa recta have penetrated the muscular layer of the colon Signup and view all the answers

The prevalence of diverticular disease approaches 50% in adults over what age in western countries?

Over 60 Signup and view all the answers

Which of the following statements about diverticular disease is true? (Select all that apply)

Associated with constipation Signup and view all the answers

Which of the following factors contribute to the pathogenesis of diverticular disease? (Select all that apply)

Low fiber diet Signup and view all the answers

Diverticular disease occurs almost always in which part of the colon?

Sigmoid colon Signup and view all the answers

Which factor significantly increases the risk of developing cancer in patients with ulcerative colitis after 10 years?

Duration of the disease Signup and view all the answers

What is a primary complication associated with toxic megacolon in ulcerative colitis?

Acute dilatation of the colon Signup and view all the answers

Which systemic manifestation is seen in ulcerative colitis that affects the gastrointestinal tract?

Ankylosing spondylitis Signup and view all the answers

What is the characteristic feature of diverticular disease?

Blind pouch formation Signup and view all the answers

What is a potential precursor to cancer in patients with ulcerative colitis?

Dysplasia Signup and view all the answers

What is the primary cause of diverticulosis in individuals following a low-fiber diet?

Increased intraluminal pressure Signup and view all the answers

Which complication of diverticulitis involves the development of hollow channels between the intestine and bladder?

Fistula formation Signup and view all the answers

Which of the following is least likely to be a symptom of diverticular disease?

Consistent diarrhea Signup and view all the answers

What anatomical feature is most commonly associated with the formation of diverticula?

Muscularis propria Signup and view all the answers

What describes the type of diverticula formed in diverticular disease?

Pseudo diverticula consisting of mucosal outpouching Signup and view all the answers

What physiological consequence results from the twisting of a loop of bowel in volvulus?

Cutting off of the blood supply Signup and view all the answers

In which demographic is sigmoid colon volvulus most commonly seen?

Elderly individuals Signup and view all the answers

Which part of the bowel is most likely to experience volvulus in younger adults?

Caecum Signup and view all the answers

What is a potential serious outcome of volvulus if not promptly addressed?

Bowel perforation Signup and view all the answers

What condition is characterized by the twisting of a segment of intestine around its mesentery?

Volvulus Signup and view all the answers

Study Notes

Learning Outcomes

Understand normal large intestine anatomy, including structure and blood supply.
Explain Hirschsprung’s disease, its causes, and clinical features.
Discuss various types and causes of colitis and their clinical presentations.
Compare Crohn's disease and ulcerative colitis.
Describe diverticular disease, adhesions, and hernias.

Large Intestine – Normal Anatomy

Length: 1-1.5 meters, comprised of the caecum, ascending, transverse, descending colon, sigmoid, and rectum.
Blood supply:
- Superior mesenteric artery nourishes from caecum to splenic flexure.
- Inferior mesenteric artery supplies the remainder of the colon to the rectum.
- Haemorrhoidal branches supply the lower rectum.

Normal Histology

Mucosa includes crypts, surface epithelium (no villi), and lamina propria.
Submucosa features loose connective tissue with Meissner's plexus.
Muscularis propria has an inner circular layer and outer longitudinal layer with Auerbach’s plexus.
Serosa consists of mesothelial cells and fibrous tissue.

Types of Mucosal Cells

Surface epithelium predominantly has columnar absorptive cells.
Goblet cells are located in crypts, secreting mucus.
Paneth cells found in the caecum and ascending colon have antimicrobial properties.
Endocrine cells secrete hormones that regulate digestive functions.

Hirschsprung’s Disease

Congenital megacolon occurring in 1 in 5000-8000 live births, more common in males (M:F = 4:1).
Frequently associated with other anomalies, like Down's syndrome (10% incidence).
Primarily affects the rectum and sigmoid colon.

Pathogenesis of Hirschsprung’s Disease

Results from arrested migration of neural crest cells, leading to absence of ganglion cells in bowel wall.
An aganglionic segment causes functional obstruction with proximal megacolon.
Genetic factors: 50% familial cases and 15% sporadic cases involve RET gene mutations.

Clinical Features of Hirschsprung’s Disease

Symptoms: failure to pass meconium, constipation, abdominal distension, vomiting.
Complications may include megacolon leading to perforation and enterocolitis; mortality rate is 5%.
Surgical resection of the affected bowel is the treatment.

Vascular Disorders

Includes ischaemic bowel disease, angiodysplasia, hereditary hemorrhagic telangiectasia, and hemorrhoids.

Ischaemic Bowel Disease

Can affect small or large intestines and present as acute or chronic disease.
Severity relies on the vessel involved; types of infarction:
- Transmural (all layers affected).
- Mural (mucosa & submucosa).
- Mucosal (only mucosa).

Dysplasia in Ulcerative Colitis

Can lead to colon cancer; regular surveillance is recommended.

Systemic Manifestations of Ulcerative Colitis

Joint issues such as migratory polyarthritis, sacroiliitis, and ankylosing spondylitis.
Skin manifestations like erythema nodosum and pyoderma gangrenosum.
Liver involvement through primary sclerosing cholangitis and symptoms of uveitis.

Diverticular Disease

Diverticula are blind pouches leading off the alimentary tract, commonly developing in the sigmoid colon.
Occurs in 50% of adults over 60 in Western countries.
Pathogenesis linked to wall stress due to low-fiber diets.

Clinical Features and Complications of Diverticular Disease

Often asymptomatic; symptoms may include abdominal pain and constipation.
Complications: diverticulitis, perforation, adhesion formation, and fistula.

Intestinal Obstruction and Associated Conditions

More common in the small bowel; mechanical causes include congenital issues, adhesions, hernias, intussusception, and stenosis.

Hemorrhoids

Variceal dilatation of submucosal venous plexi near the anus; risk factors include constipation and pregnancy.
Symptoms include bright red stool and painful swelling.

Necrotising Enterocolitis

Affects neonates; characterized by acute inflammation, most common in premature infants during the first three months.

Antibiotic-Associated Colitis (Pseudomembranous Colitis)

Defined by adherent inflammatory exudates following broad-spectrum antibiotics usage.
Symptoms include diarrhea; diagnosis through stool cytotoxin detection; treated with Metronidazole or Vancomycin.

Idiopathic Inflammatory Bowel Disease

Includes Crohn’s disease and ulcerative colitis; incidence is rising and most common in young adults.
Higher prevalence in Caucasians and Ashkenazi Jews.

Crohn's Disease

Annual incidence of 1-3/100,000 in Western populations, more common in females.
Can affect any part of the gastrointestinal tract; known for "skip lesions."

Gross and Microscopic Features of Crohn's Disease

Characterized by transmural involvement, thickening of the bowel wall, ulcers with cobblestone appearance, and chronic mucosal damage.
Microscopic features include inflammation, crypt abscesses, and possible non-caseating granulomas.

Clinical Features and Complications of Crohn's Disease

Symptoms include intermittent diarrhea, abdominal pain, and malabsorption leading to weight loss.
Complications: obstruction, fistula formation, malabsorption with deficiencies, and increased cancer risk.

Ulcerative Colitis

Chronic inflammation limited to mucosa and submucosa; mainly affects Caucasians with equal gender distribution.
Initial presentation in the rectum, progressing proximally without skip areas; features pseudopolyps and inflammatory changes.

Clinical Features and Complications of Ulcerative Colitis

Symptoms include bloody diarrhea, abdominal pain, and extra-intestinal manifestations more common than in Crohn's.
Increased cancer risk related to disease duration and extent; complications include toxic megacolon and dysplasia.

Colitis-Associated Neoplasia

Increased cancer risk correlates with disease duration, particularly after 10 years (20 times the risk).
Risk factors include the extent of the disease, with pan colitis presenting a higher risk than left-sided colitis.
Higher frequency and severity of active inflammation contributes to increased cancer risk.
Regular endoscopic surveillance with biopsy is essential for early detection.

Complications of Ulcerative Colitis (UC)

Toxic megacolon is characterized by acute colon dilation due to toxic damage affecting muscular and neural functions.
Cancer risk rises significantly with the duration of UC and extent of colonic involvement, often preceded by dysplasia.
Dysplasia particularly becomes a concern if UC duration exceeds 10 years.

Systemic Manifestations of Ulcerative Colitis

Joint Issues: Migratory polyarthritis, sacroiliitis, and ankylosing spondylitis.
Skin Conditions: Erythema nodosum, pyoderma gangrenosum, and clubbing of fingers.
Liver: Primary sclerosing cholangitis may develop.
Ocular: Uveitis can occur as a complication.

Diverticular Disease

Diverticulum: A blind pouch in the gastrointestinal tract communicating with the lumen.
Prevalence of diverticular disease approaches 50% in adults over 60 in Western countries.
Pathogenesis linked to wall stress, often associated with constipation, straining, and low fiber diets.

Pathogenesis of Diverticular Disease

A low-fiber diet results in reduced stool bulk, increasing peristaltic contractions and intraluminal pressure, leading to herniation through wall weaknesses.
Most diverticula occur in the sigmoid colon, presenting as outpouchings of the mucosa and submucosa (pseudodiverticula).

Clinical Features of Diverticular Disease

Many cases are asymptomatic; about 20% experience abdominal cramping or pain.
Symptoms may include constipation and a sensation of incomplete rectal emptying.
Treatment strategies emphasize a high-fiber diet to prevent progression and surgical intervention for complications.

Complications of Diverticulosis

Diverticulitis can ensue from obstruction, impaction, or infection of diverticula.
Other complications include perforation, abscess formation, fistulas (e.g., to the bladder), hemorrhage, and bowel obstruction.

Intestinal Obstruction

More prevalent in the small bowel due to its narrower lumen.
Mechanical causes include congenital defects like atresia or imperforate anus, as well as acquired conditions such as volvulus, adhesions, hernia, intussusception, and stenosis.

Overview of Volvulus

Volvulus refers to the twisting of a bowel loop along its mesentery.
The condition leads to compromised blood supply, causing bowel obstruction and acute ischaemia.

Common Locations for Volvulus

Sigmoid Colon
- Most frequently affected in elderly individuals.
Caecum
- More commonly occurs in young adults.

Symptoms and Risks

Twisting can result in severe pain due to obstruction.
Ischaemia increases the risk of tissue necrosis if not treated promptly.
Urgent medical intervention is often required to prevent complications.

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Description

This quiz focuses on the macroscopic and microscopic pathology of inflammatory diseases affecting the bowel, particularly for Year 2 students at RCSI. It covers topics such as the anatomy of the large intestine, Hirschsprung's disease, and various types of colitis, along with their clinical presentations.