IBD Flashcards
What is crohn’s disease?
chronic transmural inflammatory disease of GI tract
- most common in TERMINAL ILEUM
Who are more commonly affected by Crohn’s disease?
- 2nd & 3rd decade
- 6th to 7th decade
- 2 times the risk in smokers
- strong family history of Crohn’s
What are the risk factors of Crohn’s disease?
- familial aggregation
- genetic predisposition ( NOD2, HLA-B27)
- tobacco
What is the pathogenesis of Crohn’s disease?
- increased permeability of mucus membranes + abnormal immune mediated response to normal gut flora
- TH1 mediated response
- ASCA autoantibodies
What are the types of Crohn’s disease?
- terminal ileum 60%
- Colitis alone 1/3
- perianal lesions 50-75%
- stomach & duodenum 5%
What will be seen GROSSLY on exploration of Crohn’s?
- thickened grayish-pink or dull purple-red loops of bowel
- thick gray-white exudate or fibrosis of serosa
- skip lesions
- fibrotic thickening of intestinal wall (fat wrapping if circumferential)
- dilated bowel proximal to stricture
- SNAKE-LIKE/ROSE-THORN (linear mucosal ulcers)
- mesenteric abscesses & fistulae
What is the microscopic picture of Crohn’s disease?
- edema of mucosa & submucosa before any gross change
- inflammatory infiltrate extends transmurally
- NONCASEATING GRANULOMAS WITH LANGERHANS GIANT CELLS
early acute -> hyperemic & boggy
chronic -> fibrotic scarring and bowel wall thickened with leathery texture
What are the characteristic findings of Crohn’s disease?
C cobblestone mucosa R rose-thorn ulcers O obstruction of bowel H hyerplasia of mesenteric lymph nodes N narrowing of lumen S skip lesions
What are the clinical features of Crohn’s disease?
- insidious onset with slow & protracted course
- gradually becomes more frequent & severe & longer lasting attacks
- intermittent colicky abdominal pain in lower abdomen (mimics appendicitis)
- diarrhea
- perianal disease (suspect in any patient with multiple chronic perianal fistulas)
systemic symptoms - low-grade fever
- weight loss
- loss of strength
- malaise
What are the extraintestinal manifestations of Crohn’s disease?
- skin lesions -> erythema nodosum, pyoderma gangrenosum
- arthritis & arthralgias
- uveitis & iritis
- amyloidosis
- hepatitis pericholangitis
- pancreatitis
- renal or gallbladder calculi
What are the complications of Crohn’s disease?
- obstruction
- perforation
- fistulas
- localized abscesses
- toxic megacolon
- cancer
What is the DD of Crohn’s disease?
- acute appendicitis
- mesenteric lymphadenitis
- ovarian pathology
- salmonella & shigella
- intestinal TB
- acute distal ileitis
How can we confirm a diagnosis of Crohn’s disease?
CLINICAL
- history & examination
BLOOD
- CBC U&E, LFT, coagulation profile
- CRP, ESR
- ANCA & ASCA +ve
- nutritional albumin, prealbumin
STOOL
- culture & microscopy to rule out infectious colitis
- C diff toxin to rule out pseudomembraneous colitis
UGI scope & COLONOSCOPY WITH BIOPSY
- patchy inflammation
- linear ulcers
- cobble stone appearance
- stricture
MR enterography
How can Crohn’s disease be treated?
conserve by MEDICAL - steroids - aminosalicylates - antibiotics - imminomodulatory agents - monoclonal antibodies -> for severe active disease - nutritional support
ENDOSCOPIC TREATMENT OF STRICTURE
- balloon dilatation through enteroscope or colonoscope
- contraindicated if there’s an inflamed or ulcerated stricture
What are the indications for surgery in Crohn’s disease?
complications
- intestinal obstruction
- intestinal perforation with fistula formation or abscess
- free perforation
- GI bleeding
- cancer
- perianal disease
- extraintestinal manifestations
What are the principles of surgery in Crohn’s disease?
- preserve gut length & maintain adequate function
- resection kept to a minimum
- optimize patient before surgery
- surgery shouldn’t be delayed if there is a clear indication
- risk of short bowel syndrome -> stricturoplasty
- stoma formation (colostomy) incase of -> abscess, fistula, low albumin, steroid use
What are the options for surgery in Crohn’s?
- ILEOCECAL RESECTION WITH ILEOCOLIC ANASTOMOSIS -> terminal ileal Crohn’s
- SEGMENTAL RESECTION & ANASTOMOSIS -> short segment stricture with no risk of short bowel syndrome
- COLECTOMY & ILEORECTAL ANASTOMOSIS -> colonic Crohn’s with normal rectum & anus
- SUBTOTAL COLECTOMY & ILEOSTOMY -> acute Crohn’s colitis
- TEMPORARY LOOP ILEOSTOMY -> acute distal CD to allow remission and later restoration (severe perianal or rectal disease)
- PROCTOLECTOMY -> colic/anal disease failing to respond to medical treatment (permanent ileostomy)
- STRICTURE PLASTY -> multiple areas of CD & danger of short bowel syndrome
What is ulcerative colitis?
- dynamic disease characterized by remissions & exacerbation
- peak incidence 15-35 years then >55 years
What are the risk factors of ulcerative colitis?
- genetic (HLA-B27)
- ethnicity (white & Ashkenazy jews)
- family history
- previous intestinal infection
- increased fat intake
- OCPs & NSAIDS
What are the protective factors against ulcerative colitis?
- appendectomy before established UC
- smoking
What is the pathogenesis of ulcerative colitis?
- increased permeability of intestinal epithelium
- TH2 differentiation
- dysregulation of immune system
- ANCA against epithelial cells
- CONTINUOUS UNINTERRUPTED INFLAMMATION OF COLONIC MUCOSA beginning in distal rectum & extending proximally
What is the gross picture of ulcerative colitis?
- hyperemic mucosa
- friable & granular mucosa -> in severe
- ulcerations
- pseudopolyps or inflammatory polyps
What is the microscopic picture of ulcerative colitis?
- inflammation of mucosa & submucosa
- CRYPT ABSCESS
What is the most common course of ulcerative colitis?
CHRONIC INTERMITTENT
- exacerbation followed by complete remission
chronic continuous
- no complete remission
acute fulminant
- sudden onset of severe diarrhea, dehydration & shock
What are the symptoms of ulcerative colitis?
- bloody diarrhea with mucus
- fecal urgency
- abdominal pain & cramps on left side
- tenesmus
what are the extra-intestinal manifestations of ulcerative colitis?
- osteoarthritis, ankylosing spondylitis, sacroiliitis -> skeletal (most common)
- uveitis, episcleritis, iritis -> ocular
- primary sclerosing cholangitis -> biliary
- pyostomatitis vegetans, apthous stomatitis, erythema nodusom, pyoderma gangrenosum -> cutaneous
- fatigue & fever
- growth retardation & delayed puberty in children
What are the complications of ulcerative colitis?
- acute fulminant colitis
- toxic megacolon
- colonic cancer (greater risk with longer disease)
How should the diagnosis of ulcerative colitis be confirmed?
BLOOD
- increase ESR & CRP
- leukocytosis
- anemia
- thrombocytosis
- increase pANCA
STOOL
- search for bacteria to rule out infectious causes
COLONOSCOPY (definitive diagnosis)
- contraindicated in acute
RADIOGRAPHY plain
- loss of colonic haustrata (LEAD PIPE APPEARANCE in severe)
- massive distention in toxic megacolon
- pneumoperitoneum if perforated
BARIUM ENEMA
- able to detect early changes
- granular appearance of mucosa
- deep ulcerations
- loss of haustra
- pseudopolyps appear as filling defects
CT -> wall thickening if severe
MRI -> extent of involvement
ULTRASOUND -> bowel thickening (absent hyperechoic reflection from lumen)
What is the DD of ulcerative colitis?
- Crohn’s disease
- exudative-inflammatory diarrhea
- diverticular disease
- ischemic colitis
- infectious colitis
- radiation colitis
- celiac disease
How should ulcerative colitis be managed?
- first -> conserve with drugs to induce & maintain remission
- if medical fails -> curative proctocolectomy
What is the initial management of ulcerative colitis?
PROCTITIS
- 5ASA + steroids
- immunosuppressant + monoclonal antibodies
ACUTE COLITIS
- mild -> steroids + 5ASA
- moderate -> oral steroid + steroid enema + 5 ASA
- severe -> NPO, IVF, IV antibiotics, steroid -> not improving? -> emergency surgery
What are the indications for surgery in ulcerative colitis?
- fulminant colitis with toxic megacolon
- massive bleeding
- intractable disease
- dysplasia or carcinoma
- malnutrition & growth retardation
- extraintestinal manifestations
- failure of medical
What are the surgical treatment options for ulcerative colitis?
EMERGENCY -> in systemic upset, malnourished patient, or on steroids
- total colectomy with end ileostomy
- no dissection of rectum (mucus fistula)
- restorative surgery later
ELECTIVE -> sphincter problems, lower complication rate, no risk of rectal cancer
- restorative proctocolectomy with ileal pouch anal anastomosis (IPAA) -> pelvic sepsis
- colectomy with ileorectal anastomosis -> if minimum rectal inflammation with rectal checkups
