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An autoimmune disorder of the small intestine characterized by a permanent intolerance to wheat gluten that results in mucosal damage and malabsorption.
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Prevalence: 1 in 300 worldwide
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More common in persons of European descent
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Associated with juvenile-onset diabetes mellitus, selective IgA deficiency, dermatitis herpetiformis, autoimmune thyroid disease, Down syndrome, Turner syndrome, and Williams syndrome
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Increased prevalence in children with first-degree relatives with celiac disease
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Increased risk of small bowel lymphoma
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Gut exposure to grain proteins in wheat, rye, barley, and oats results in an autoimmune reaction that is toxic to enterocytes and leads to a flattened mucosal lining and impaired small intestinal absorptive capacity
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CLINICAL MANIFESTATIONS
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Symptoms are variable and can present at any age
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Classically presents around age 1–3 years, but this is changing as more children are identified by increased screening practices
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Diarrhea, foul-smelling bulky greasy stools, abdominal distention and pain
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Poor growth, anorexia, malaise, muscle wasting, irritability, unexplained iron deficiency anemia
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Symptoms can be subtle with only mild diarrhea or recurrent abdominal pain or constipation complaints
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Physical exam: Weight loss, short stature, edema, abdominal distention, rectal prolapse, muscle wasting, dental erosion, angular stomatitis, aphthous lesions, osteopenia, rickets
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Antibody Tests: Anti-gliadin antibody (IgA and IgG; moderate sensitivity, low specificity), anti-endomysial IgA (sensitivity = 90–95%, specificity = 98–100%; false-negative results more common in children younger than 2 years of age), anti-tissue transglutaminase antibody (IgA anti-tTG; sensitivity = 92–98%, specificity = 96–100%)
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Antibody tests are good for initial screen but endoscopy required for definitive diagnosis
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Anti-gliadin antibodies are not used for standard screening, except in the young child less than 2 years old. Deamidated anti-gliadin antibody is more sensitive and specific than previous standard test
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May present with elevated hepatic transaminases
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Endoscopy: Small bowel biopsies on a gluten-containing diet help make diagnosis; increased epithelial lymphocytes, villous atrophy, crypt hyperplasia, infiltration of lamina propria with inflammatory cells are features consistent with celiac disease; resolution of abnormalities on gluten-free diet confirms diagnosis
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Permanent gluten-free diet leads to full clinical and histologic remission; gluten-free means no wheat, rye, barley, or oats; corn and rice are permitted
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Dietary counseling and careful attention to ALL food and medicinal products that may contain traces of gluten
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Multivitamin/fat-soluble vitamins
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Medical therapy for iron deficiency and rickets if present
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Very close follow-up of growth parameters and symptoms
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Periodic monitoring of dietary compliance with antibody profile; antibodies usually undetectable within 3–6 months after initiation of appropriate diet
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Screening of all immediate family members is indicated
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A symptom of abnormal defecation characterized by infrequent stooling, incomplete evacuation of the rectum, passage of large painful stools, involuntary soiling, or the inability to pass stool.
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Occurs in more than 10% of all children
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Majority of constipation in older children is functional
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Encopresis occurs in 1–2% of all children
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Anatomic: Hirschsprung disease, imperforate anus, anal stenosis, malpositioned anus, ileal atresia, meconium ileus, colonic stricture, abdominal mass, hydrometrocolpos
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Physiologic: Hypothyroidism, celiac disease, lumbosacral spinal cord defect, infant botulism, muscular diseases, cystic fibrosis, diabetes, lead poisoning, post-viral “ileus,” prune-belly syndrome, ascariasis, medications, excessive cow’s milk ingestion, inadequate fluid intake, malnutrition, anorexia nervosa, functional constipation
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Functional Constipation: Cycle typically begins with voluntary withholding of stool. Stool returns from anal canal to rectum. Sensation of urge to defecate is decreased. Stool bolus becomes larger and harder, which perpetuates more withholding. Over time, rectal vault distends and normal sensation diminishes
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Retentive Encopresis: Involuntary soiling of liquid stool around solid stool, which results from chronic constipation
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Grunting Baby Syndrome: An infant with grunting, straining, and turning red while passing a soft stool has immature coordination of the stooling process and not true constipation
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CLINICAL MANIFESTATIONS
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Signs of possible anatomic abnormalities: Blood in stool, failure to thrive, emesis, abdominal distention
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Signs of functional constipation: Retentive posturing; infrequent passage of large, hard bowel movements; involuntary soiling
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Complaints of abdominal pain
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Stool consistency may be hard, soft, or even diarrheal
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Stool frequency can be daily or infrequent
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On physical exam, note abdominal tenderness/distention, palpable stool on abdominal palpation, anal wink, anal tone, stool in rectal vault, width of rectal vault, neurologic and back exams
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1-view abdominal x-ray: Most useful to diagnose fecal impaction in the rectum. Limited use in correlating colonic stool burden with degree of constipation
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Radiopaque Sitz Marker study: Child swallows 24 radiopaque markers in one sitting and x-ray obtained 5 days later. Location of markers aids in determining type of constipation. May be done to assess a current bowel regimen or following a bowel clean-out to assess GI transit without stool burden
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✓ Slow transit: Markers distributed throughout the colon
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✓ Outlet dysfunction: Numerous markers clustered in rectosigmoid
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✓ Functional: Less than 3 markers remaining on x-ray
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Unprepped Contrast Enema/Rectal Biopsy: To evaluate for Hirschsprung disease
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L-spine MRI: Suspected spinal cord abnormality
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Treat underlying medical disorders
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Surgical correction of anatomic defects
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Treatment of functional constipation may take months to years
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✓ Bowel clean-out: Enemas, suppositories, lubricants, hyperosmolar agents
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✓ Maintenance: Dietary fiber and fluids, hyperosmolar agents
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✓ Toilet sitting: Twice-daily stooling attempts
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✓ Diary/journal: Positive reinforcement
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✓ Educate patient and parents. Frequent follow-up is critical to success
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Medications used to treat constipation:
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✓ Enema: Mineral oil (rectally); sodium biphosphate (Fleets); or saline; all in children ≥2 years of age. Larger volume enemas such as polyethylene glycol enemas to relieve rectal fecal impaction may be necessary
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✓ Suppositories: Glycerin, bisacodyl
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✓ Lubricants: Mineral oil (orally)
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✓ Osmotic laxatives: Polyethylene glycol (PEG) 3350 (Miralax), lactulose, PEG with electrolytes (Go-Lytely)
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✓ Stimulant laxatives: Senna, bisacodyl, magnesium citrate, magnesium hydroxide
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✓ Fiber/bulk forming agents: Benefiber, Citrucel, Metamucil, Maltsupex
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GASTROINTESTINAL BLEEDING
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Loss of blood via the GI tract:
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Hematemesis: Bloody emesis due to active bleeding proximal to the ligament of Treitz
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Hematochezia: Bright red or maroon stool due to active bleeding in the colon or brisk bleeding from a more proximal site
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Melena: Dark, tarry stool due to bleeding proximal to the ileocecal valve
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DIFFERENTIAL DIAGNOSIS
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CLINICAL MANIFESTATIONS
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Variable presentation from hemodynamically stable to shock
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Note prior use of NSAIDs, steroids, indomethacin, antibiotics
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Note history of trauma, liver disease, umbilical vein catheterization (history of umbilical vein catheterization is associated with portal vein thrombosis and development of portal hypertension predisposing to esophageal varices)
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May present with vomiting, retching, casual regurgitation of bloody fluid, abdominal pain, anorexia, fever, weight loss, sepsis, asphyxia, recent surgery, mental status changes
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Inspect mouth, nares, pharynx for trauma
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Abdomen: Hepatomegaly, splenomegaly, prominent abdominal vessels, right lower quadrant mass or tenderness
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Rectal: Blood, erythema, fissure, fistula, skin tag, polyp, hemorrhoid, rectal prolapse
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Stool: Blood or mucous within or surrounding stool
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Extremities: Capillary refill, digital clubbing, palmar erythema, purpura, or petechiae
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Skin: Pallor, jaundice, facial petechiae, pigmented freckles on lips/buccal mucosa, excoriations, hemangiomas, other vascular appearing lesions
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For breastfeeding infant, inspect mother’s nipple (dry, cracked, bleeding nipples suggest swallowed maternal blood)
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Stool guaiac: False-positive results may be due to rare meat, horseradish, turnips, iron, tomatoes, fresh red cherries; false negatives may be due to vitamin C, outdated card or developing solution, storage of stool greater than 4 days
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Nasogastric lavage: Use normal saline at room temperature; absent blood does not exclude an upper GI source; present blood does not identify the exact origin
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Laboratory studies: CBC, PT/PTT, LFTs, electrolytes, type and screen
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Stool bacterial culture and stool C. difficile toxins
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Abdominal x-ray: Free air, toxic megacolon, pneumatosis, small bowel dilation
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Air or gastrograffin contrast enema: For suspected intussusception
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Meckel diverticulum scan
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Upper GI series: Structural abnormality, tumor, polyp, signs of IBD
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CT/MR angiography studies useful in both slower and brisk bleeding to localize lesion. CTA with oral contrast (CT Enterography) is most sensitive test if patient can tolerate oral contrast
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Tagged Red Blood Cell bleeding scan and Angiography reserved for brisk bleeding without clear localization on imaging studies
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Endoscopy or colonoscopy: Direct visual inspection, biopsy, culture
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Wireless video capsule endoscopy: For small bowel obscure GI bleeding
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Initial Management of all GI Bleeding: Identify and treat shock with IV access, isotonic fluids, oxygen, blood products
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Non-Variceal Upper GI Bleed: Acid reduction (ranitidine, pantoprazole); discontinue NSAIDs; endoscopic hemostasis therapy if bleed persists (bipolar electrocoagulation, heater probe, clips, injection therapy)
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Variceal Upper GI Bleed:
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✓ Fluid resuscitation; transfuse red cells to maintain hemoglobin near 10 g/dL; transfuse platelets to greater than 50,000/mm3; FFP to correct coagulopathy
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✓ Octreotide (bolus 1–2 μg/kg over 2–5 minutes, then 1–2 μg/kg/h infusion): Reduces splanchnic arterial blood flow to decrease portal pressure
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✓ Endoscopic band ligation, sclerotherapy
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✓ Emergent surgical therapy for unresponsive severe bleeding: Portosystemic shunt, trans-jugular intrahepatic portal shunt (TIPS), Blakemore–Sengstaaken tube occlusive balloon therapy, liver transplantation
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Lower GI Bleed in an Infant:
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✓ Surgical evaluation for suspected intussusception, necrotizing enterocolitis, toxic megacolon, Hirschsprung disease
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✓ If otherwise healthy and has blood-streaked mucus in stool without evidence of fissure, send stool culture and consider changing to elemental formula for presumptive milk-protein allergy
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✓ Flexible sigmoidoscopy for persistent bloody stools despite elemental formula and negative stool culture
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✓ Anal fissures heal without intervention
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Lower GI Bleed in an Older Child:
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✓ Treat according to underlying cause if known
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✓ Treat constipation if present
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✓ Flexible sigmoidoscopy or colonoscopy for recurrent or persistent bleeding to detect colitis, polyps, IBD
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✓ Polyp removal by electrocautery
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✓ Meckel scan if no source identified by endoscopy
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✓ Surgical evaluation if severe bleed of unidentified source
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INFLAMMATORY BOWEL DISEASE
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An idiopathic chronic disease of the GI tract resulting in inflammation, tissue destruction, diarrhea, protein-losing enteropathy, GI bleeding, abdominal pain, and many extraintestinal manifestations. IBD is broadly divided into Crohn’s disease, ulcerative colitis (UC), and indeterminate colitis (IC).
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Family history predisposes to IBD
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20–30% of new IBD presents in persons younger than 20 years of age
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4% of pediatric IBD presents in children younger than 5 years of age
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More common in developed countries
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Interaction between environmental, gut microbiota, immunologic and genetic factors
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Dysregulation of mucosal immune system driven by normal intestinal flora
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Crohn’s Disease:
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✓ May involve any segment of the GI tract, mouth to anus
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✓ Commonly involves small intestine and terminal ileum
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✓ Transmural disease with thickened nodular bowel, non-caseating granulomas, strictures, fistulas, abscesses, adhesions
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✓ Skip lesions, discontinuous disease
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✓ Perianal disease (15%)
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✓ Malabsorption of iron, zinc, folate, and vitamin B12
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✓ Bacterial overgrowth
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✓ Carcinoma (increased risk over general population)
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Ulcerative Colitis:
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✓ Limited to the colon; starts in rectum and ascends continuously
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✓ Diffuse mucosal involvement/submucosal sparing
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✓ Crypt abscesses; toxic megacolon (<5%)
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✓ Carcinoma (significant increased risk over general population)
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Indeterminate Colitis:
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CLINICAL MANIFESTATIONS
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Intestinal Manifestations:
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Crohn’s disease: Abdominal pain, diarrhea, rectal bleeding, aphthous oral lesions, perianal fissures/tags/fistulas, abdominal abscesses, anorexia, weight loss, linear growth deceleration
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Ulcerative colitis: Bloody mucoid diarrhea, lower abdominal pain/tenderness, urgency to defecate, nausea/vomiting associated with defecation
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Extraintestinal Manifestations:
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Occur in approximately 30% of patients with IBD, more typically after IBD diagnosis is made. A minority will manifest extraintestinal symptoms prior to intestinal-related symptoms.
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Systemic: Fever, malaise, anorexia, weight loss, growth delay/linear growth deceleration, delayed puberty
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Skin: Erythema nodosum, pyoderma gangrenosum, perianal disease
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Joints: Arthritis, arthralgia, clubbing, ankylosing spondylitis, sacro-ileitis
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Eyes: Uveitis, episcleritis, keratitis, retinal vasculitis
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Biliary: Sclerosing cholangitis (UC > crohn’s disease), chronic active hepatitis, fatty liver, cholelithiasis
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Bone: Osteopenia
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Renal: Stones, hydronephrosis, enterovesical fistula
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Vascular: Thrombophlebitis, vasculitis
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Heme: Anemia (iron, vitamin B12, folate deficiency, hemolysis, marrow suppression from medications, anemia of chronic disease), thrombocytosis, neutropenia
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Oncologic: Lymphoma, acute myelogenous leukemia, colon cancer
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Complete blood count (low hemoglobin, low mean corpuscular volume, high platelets), ESR (high), C-reactive protein (high), albumin (low), alkaline phosphatase (low), iron studies, folate, vitamin B12 levels, electrolytes, calcium, magnesium, phosphorus
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Unique IBD-related antibody serologies are sometimes used to aid the differentiation of crohn’s disease and UC when unclear. ASCA (anti-Saccharomyces cerevisiae antibody) and ANCA are most well described, although other antibodies are now available. These antibodies are generally not used as screening tests to evaluate for IBD
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Stool guaiac: Positive
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Stool for culture, C. difficile toxins A and B, ova and parasites, cryptosporidium and Giardia
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Fecal calprotectin is highly sensitive and specific for GI tract inflammation, especially colitis. Highly valuable in distinguishing between IBD and irritable bowel syndrome (IBS)
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✓ When a combination of the above tests raise suspicion for IBD, the gold standard test to rule out the disease is endoscopy and colonoscopy. A radiology study (see below) may be chosen before endoscopy/colonoscopy depending on presenting symptoms (concern for obstruction, abscess, perforation)
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There is no one perfect imaging study to evaluate the small bowel in patients with IBD. Each study has its benefits and limitations. The optimal initial study depends on the patient and his/her symptoms and course of illness.
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Upper GI with small bowel follow-through: Useful to evaluate for strictures. False-negatives common for superficial mucosal disease
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Abdominal CT: Useful to assess for complications of crohn’s disease such as intra-abdominal abscess or phlegmon
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MR Enterography: MRI of bowel with IV and oral contrast. No ionizing radiation. Useful to assess transmural disease
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MRI Pelvis: Frequently used to assess perianal disease and fistulae
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Wireless video capsule endoscopy: Useful to assess the mucosal surface, unable to assess disease beyond bowel lumen. Risk of capsule retention at site of narrowing/stricture. A test capsule is available for those considered at higher risk
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Bone Age: Assess for delayed bone maturation
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DXA Scan: Assesses bone mineral density, which may be low in chronic inflammatory diseases such as IBD. Normal range: Z score +2 to −2. Below Z − 2, patients may be at risk for fracture
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Gold standard for diagnosis
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Mucosa may appear erythematous, edematous, friable, ulcerated
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Loss of normal vascular pattern
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Well-established diagnostic histology criteria—Chronic inflammation, crypt abscesses, architectural mucosal abnormalities, etc
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Choice of therapy for a given patient depends on many factors including disease phenotype, location of disease, severity of symptoms, growth status, age of patient, and among other factors. “Bottom up” (salicylates, steroids, antibiotics), “top down” (biologics, immunomodulators), or use of enteral therapy at time of newly diagnosed IBD may be appropriate depending on the above factors.
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Salicylates: Sulfasalazine, mesalamine (Pentasa, Delzicol), balsalazide (Colazal), rowasa (enemas), canasa (suppositories)
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Antibiotics: Metronidazole, ciprofloxacin, rifaximin, oral vancomycin
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✓ Antibiotics are indicated in setting of penetrating (fistulizing) luminal or perianal disease and comorbid C. difficile infection
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✓ Use in active luminal crohn’s disease and UC as adjunctive therapy is patient-specific. Metronidazole and ciprofloxacin have each been shown to improve symptoms in some studies while lack significant benefit in others
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Steroids: Prednisone, methylprednisone, budesonide (ileal release with less systemic absorption), budesonide MMX (Multimatrix system technology; colonic release with less systemic absorption) hydrocortisone enema
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Immunomodulators: To reduce steroid dependency or as adjunct to infliximab
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Biologic agents: Moderate to severe crohn’s disease or UC, fibrostenotic or fistulizing crohn’s disease, steroid refractory UC, other indications
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✓ Infliximab (Remicade), adalimumab (Humira), certolizumab pegol (Cimzia)
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✓ Obtain PPD/CXR to rule out latent TB infection before initiation
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✓ Make sure vaccination series completed
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Enteral nutritional therapy: Nutritional-based therapy for crohn’s disease, typically with delivery of semi-elemental formula via NG tube. May modulate gut microbiota to favor anti-inflammatory response. Given as 80–100% of daily caloric intake to induce remission of disease
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In acute severe UC, use of the PUCAI (pediatric UC activity index) scoring system of symptoms can guide clinical judgment regarding response to therapy and need to escalate therapy. The scoring includes abdominal pain, rectal bleeding, stool consistency, number of stools per day, nocturnal bowel movements, and activity level
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Discharge criteria following acute flare include improvement of presenting symptoms (e.g., tolerating oral intake without severe pain, minimal gross blood in stool and maintaining stable hemoglobin level, fewer diarrheal stools, gaining weight if admitted with weight loss, resolution of emesis, resolution of obstruction)
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Indicated in uncontrolled bleeding, bowel perforation, bowel obstruction, intractable disease, and intractable perianal disease
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Crohn’s disease: Local resection (such as ileocecectomy), ostomy diversion, fistula management
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✓ Incision and drainage of perirectal abscesses +/− drain placement
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✓ Seton: A suture is placed through the fistulous tract forming a loop, to allow for continuous draining and healing from lumen to skin. Without seton, fistulous tracts tend to heal at the skin side first, and pus may be trapped creating an abscess
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UC: Total colectomy with ileo-anal anastomosis for medically refractory disease
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MECKEL’S DIVERTICULUM
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A true diverticulum that results from incomplete closure of the omphalomesenteric or vitelline duct. It may contain gastric or other mucosa, and occurs along the ileum usually within 100 cm of the ileocecal valve.
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Persistence of vitelline duct; contains all three intestinal layers
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May contain ectopic tissue: Gastric (50%), pancreatic (5%), other
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Bleeding occurs when acid secreted by ectopic gastric mucosa causes adjacent ileal ulceration or erodes into the vitelline artery
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CLINICAL MANIFESTATIONS
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Asymptomatic: 95% of cases
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Painless lower intestinal bleeding: Most common symptom accounting for 50% of symptomatic presentations, generally in patients 2 months–2 years
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Other manifestations: Intestinal obstruction, intussusception, volvulus, herniation through mesenteric defect, severe right lower quadrant abdominal pain (Meckel’s diverticulitis), umbilical cysts/sinuses, palpable abdominal mass
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Technetium-99m pertechnetate scintigraphic study. Test has high specificity (95–100%) but lower sensitivity (50–92%). Use of H2 receptor antagonist (ranitidine) prior to test may increase yield with a sensitivity of 62.5% with conventional study, and sensitivity of 87.5% when pretreated with ranitidine
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Tagged red blood cell scan if active bleed
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Upper GI with small bowel follow through
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Wireless video capsule endoscopy may identify isolated ileal ulcer
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Barium enema (if intussusception suspected)
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Occasionally discovered as incidental finding at laparoscopy
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Medically resuscitate the patient with a lower GI bleed
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Symptomatic Meckel’s diverticulum should be surgically resected
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Meckel’s diverticulum found incidentally during surgery performed for another reason should be resected if there is are palpable heterotopic mucosa or mass, fibrous bands to umbilicus, or surrounding inflammation