GIT 2 New Dr. Basu. Topic Malabsorption Diarrhea and Dysentery IBD –Ulcerative colitis –Crohns disease.

GIT 2

New

Dr. Basu

Topic

• Malabsorption

• Diarrhea and Dysentery

• IBD– Ulcerative colitis– Crohns disease

Malabsorption : Classification

• Diagnosis: Steatorrhea, fat soluble vitamin Deficiency, protein and other deficiency.

1. Celiac sprue

2. Whipple disease

3. Disaccharide deficiency

Celiac sprueCeliac sprue

(chronic sprue)

Antigen involved: gluten. Genetic- HLA-DQ2 or HLA-DQ8.

Morphology Atrophy of Villi, increased number of intraepithelial lymphocytes ( CD4 and CD8 cells).

Clinical Diarrhea, flatulence, weight loss, and fatigue, dermatitis

Respond to gluten free diet.

Atrophy of VilliNormal

Complication of celiac sprue: Dermatitis Herpitiformis and NHL.

Tropical sprue

• Definition : malabsorption due to unknown ( ? Infection) etiology.

• Location: Caribbean and South America

• Treatment: antibiotics and B12 supplements.

WHIPPLE DISEASE

WHIPPLE DISEASE

Etiology: Bacterium Tropheryma whippelii

Morphology Macrophages contain PAS-positive, diastase-resistant granules and rod-shaped bacilli on electron microscopy

Other organ involvement

GIT, CNS, Joint and lymph nodes

Clinical Features

Age: 40-50 yr.

Malabsorption, Arthropathy, psychiatric complaints and Lymphadenopathy.

Electron microscopyLight microscope (H&E)Foamy macrophage in villi.

LACTASE DEFICIENCY

Etiology : Atrophy of the apical villous cells>deficiency of lactase.Clinical :

The infants develop explosive, watery, frothy stools and abdominal distention.Osmotic diarrhea with milk product.

Termination of which result in recovery.

Vitamin deficiency

Vitamin A Night blindness, xerophthalmia, blindness, Squamous metaplasia, infection.

Vitamin K Bleeding diathesis- not corrected by k injection.

Vitamin D Rickets in children, Osteomalacia in adults.

Vitamin E Spinocerebellar degeneration

Vitamin B12 Megaloblastic pernicious anemia and myelin loss of spinal cord tracts.

DIARRHEA AND DYSENTERY

DIARRHEA AND DYSENTERY

• DIARRHEA Def; An increase in stool mass, stool frequency, and/or stool fluidity are perceived as diarrhea.

• DYSENTERY: Dysentery is a severe diarrhea illness often associated with blood in the feces.

Diseases

Viral enterocolitis Rota virus (dsRNA): child and self limiting.

Adenovirus (dsDNA): adult /child

E. coli - Shiga-like toxin (Undercooked beef products: hamburger)

Hemorrhagic colitis and

Hemolytic-Uremic syndrome (HUS): Hemolysis, Acute Renal failure and DIC.

Others

• Staphylococcus aureas : – Source is milk product and fatty food → Acute

explosive Exudative diarrhea.– Within a few hours (1-6 hr)

• Vibrio cholera: – Source is Water → Watery diarrhea, cholera,

pandemic spread.– Morphology of GI: normal mucosa

Cholera: pathogenesis of diarrhea

Cholera toxin A1↓

A1+ ADP-ribosylation factors (ARF)↓

catalyzes G protein ↓

stimulates adenylate cyclase ↓

high levels of intracellular cAMP ↓

stimulates secretion of chloride and bicarbonate, with associated sodium and water secretion.

Others Salmonella enteritidis→

Milk, beef, eggs, poultry

Self limiting diarrhea / dysentery pain, bacteremia.

Incubation: 12 to 72 hr

Shigella: Person-to-person. Milk, poultry

S. flexneri infection produce Reiter syndrome (chronic arthritis , red eye- conjunctivitis).

Fever, pain, mucosal ulcer.

Exudative diarrhea ,dysentery, epidemic spread

Clostridium difficile

Clostridium difficile →

Following antibiotic use, nosocomial acquisition: Cytotoxin, local invasion

Fever, pain, bloody diarrhea, pseudo membrane formation over mucosa.

Neural reflex pathways increases epithelial fluid secretion In addition to

production intracellular cAMP

Pseudomembranous colitis from C. difficile infection morphology

Study unknown picture

Campylobacter Enterocolitis

Source: dog, ingestion of improperly cooked chicken.

Clinical: Diarrhea, dysentery.

Complications:

Reactive arthritis in HLA-B27 carriers

Guillain-Barré syndrome- myelin loss (PNS).

C. jejuni: immunoproliferative small intestinal disease.

Amebiasis

Agent Entamoeba histolytica (ameba)

Route Fecal oral

Morphology Produce flask shaped ulcer in submucoca.

Clinical features

Abdominal pain, bloody exudative diarrhea, or weight loss and amebic liver abscess- right upper Q pain.

Rest a while

Other intestinal disorders

• Necrotizing Enterocolitis

• Idiopathic Inflammatory Bowel Disease

Necrotizing Enterocolitis

Definition An acute, necrotizing inflammation of the small and large intestines

Age Neonate : premature or of low birth weight, when infants are started on oral foods

Necrotizing Enterocolitis

Pathogenesis: factor• Intestinal ischemia

Clinical course : Bloody stools, abdominal distention, and development of circulatory collapse.

Site: involves the terminal ileum, cecum, and right colon.

Morphology of the gut: gross and micro

• Distended, friable, and congested, or it can be frankly gangrenous.

• Accompanying peritonitis may be seen.

• Morphology: sub mucosal gas bubbles formation.

Distended intestine

Submucosal gas bubbles

Prognosis

• High mortality

• Post-NEC stricture is COMMON.

Idiopathic Inflammatory Bowel Disease

• Type

• Pathogenesis

• Comparative morphology of these two diseases

• Complications and clinical features

• Diagnosis

IBD• Types:

– Crohns disease– Ulcerative colitis

• Pathogenesis:A. Exaggerated local CD4 T-Cell immune

response- damage to mucosa

B. Inflammation

Crohn disease

• Features:– Occur any part of GIT– Transmural inflammation .– Noncaseating granulomas.– Fissuring with formation of fistulae.– Smoking is a risk factor.– Recurrent diarrhea, pain, fever common.– Blood in stool 50%.

Ulcerative colitis

• Features:

– Disease limited to the colon and affecting only the mucosa and sub mucosa.

– Smoking is a risk factor.

– Bloody mucoid diarrhea more common.

Gross Crohn disease ( gross) Ulcerative colitis ( gross)

Any part of bowel : common in ileocecal junction (regional ileitis)

Large intestine: Pan colitis.

Rectum→ colon: back wash ileitis

Produce “skip” lesions.

Transmural inflammation.

No skip lesion, entire length of bowel is involved.

Mucosal involvement

Cobblestone effect Pseudo polyps

GrossCrohn disease ( gross) Ulcerative colitis

( gross)

Diseased wall is rubbery and thick

Mural thickening does not occur in UC

Linear ulceration Broad-based ulceration

Mesenteric fat wraps around the bowel surface (creeping fat).

No such features

Crohn disease : Diseased wall is rubbery and thick and lumen is narrow that give rise to

String sing on X-ray

Study unknown picture

Gross of Ulcerative colitis :Pseudopolyps

Microscopy of IBD

Crohn disease Ulcerative colitis

Non Caseating granuloma

Crypt abscess

Pseudopolyps

Dysplasia +

Ulcerative colitis; crypt abscess and glandular

architectural distortion and dysplasia.

Study unknown picture

IBD: complication

Ulcerative colitis Crohn's

Complication:

Toxic megacolon

Adenocarcinoma.

Complication:

Fistula and fissure, obstruction

Fistula with other organ like U. Bladder, vagina and, skin (Enteroculaneous fistula)

Toxic mega colon in UC

No motility, lead pipe

Crohn disease: Fissure

Extra intestinal manifestation of IBD

Crohn disease Ulcerative colitis

Migratory poly arthritis ++.

Aphthous ulcer.

Migratory poly arthritis ++++

Uveitis++++++++

Erythema nodosum (painful skin lesion- show similar granuloma)

Hepatic primary sclerosing Cholangitis +++++++

Diagnosis/ treatment of IBD

Crohn disease Ulcerative colitis

Surgery not helpful Surgery helpful with steroid

pANCA : + pANCA: ++++++++,

HLA B27

Irritable Bowel Syndrome

• Intrinsic motility disorder ( ? Due to foods, stress- serotonin).

• Clinical: altered bowel habits, frequently suffering from constipation, diarrhea, or both.

• The episodes may subside with a bowel movement

Thank you