Gastro - Ulcerative Colitis and Crohn's Disease Flashcards
What is inflammatory bowel disease?
IBD is make up of ulcerative colitis and Crohn’s disease
What parts of the colon does Crohn’s disease affect? What parts of the colon does Ulcerative Colitis affect?
Crohn’s – any part of GIT and has skip lesions where part of inflamed area and then normal then affected etc. The part that is most affected is the ileum, then colon
Rectum is unlikely to be affected.
Ulcerative Colitis
Only affects large intestine. Starts at rectum and spreads continuously up the colon. If it affects the entire colon it is known as pancolitis
Sx of Crohn’s disease and Ulcerative Colitis?
Crohn’s
- Diarrhea (can be blood or non-bloody mostly 2) watery due to malabsorption.
- RLQ pain due to location of terminal ileum
- Relapse remitting of Sx coming and going
- Transmural ulcers (from mucosa to serosa)
- Granulomas in ulcers
- Steatorrhea
Ulcerative Colitis
Bloody diarrhea (haematochezia)
LLQ pain
Feeling of incomplete pooping (tenesmus)
Pathophysiology of Crohn’s disease?
Transmural ulcer where it eats through epithelium, lamina propria, muscularis mucosa (these 3 make up mucosa), connective tissue with glands (submucosa), muscularis externa (muscle layer)
Granulomas occur due to TH1 cells releasing cytokines such as TNF alpha and Interferon gamma. This causes inflammation in the area which overtime erodes the wall of the GIT
TH1 also releases cytokines Interleukin 12 and 23 which activate TH17 cells which increase neutrophil upregulation which further increases inflammation
Pathophysiology of UC?
Submucosal Ulcers – Ulcers only extend as far as mucosa and submucosa.
NO granulomas
Immune dysregulation by TH2 cells releasing cytokines TNF alpha and IL 4, IL 5 propagate inflammation. Most important cytokine is TNF alpha
Causes of Crohn’s disease and Ulcerative Colitis?
Crohn’s
Fam Hx of IBD
Mutation in NOD-2 gene
Western Diet
Smoking – increased risk of Crohn’s flareups
UC
Fam Hx of IBD
HLA mutation (DRB 1)
Western Diet
smoking – decreases UC flares
Dx of IBD
Pain – RLQ OR LLQ
Diarrhea – watery or bloody
Tenesmus supportive of UC
String sign supportive of CD
Ileocolonoscopy with biopsy – skip lesions or cobble stone appearance shows Crohn’s.
Barium enema – Lead pipe sign
NEVER DO BARIUM ENEMA IF SUSPECT TOXIC MEGACOLON
colonoscopy with biopsy – friable colon mucosa that is continuous with lesions
biopsy with ulcers only extending until submucosa instead of serosa shows UC instead of CD
(image on doc)
How can you tell if a pt is having a flare up of UC or CD or something else? What would you be trying to rule out?
Trying to rule out mainly IBS and infectious diarrhea and more specifically trying to rule out small bowel obstruction from CD flareup and toxic megacolon and UC flare.
The main diagnostic techniques used in this ddx would be abdo xray, fecal calprotectin, ESR, CRP, stool culture, O&P (ova and parasites exam). C.diff assay.
Xray not showing dilated bowel loops or air fluid levels rule out SBO.
X ray not showing dilated colon (>6cm) or pneumoperitoneum rule out toxic megacolon
Increased levels of fecal calprotectin, ESR and CRP indicate that it is not IBS and is IBD. This is because raised levels of these mean there is inflammation of the bowel wall.
Negative stool analysis rules out infectious diarrhea
Complications of Crohn’s disease
Malabsorption – decreased fat absorption decreased absorption of fat soluble vitamins Vit ADEK deficiencies night blindness, osteoporosis, haemolytic anemia, bleeding due to lack of coagulation proteins respectively
Foul smelling stools (steatorrhea) due to malabsorption of fats
Increased oxalate due to decreased fats so increased incidence of oxalate kidney stones
Bile acids not absorbed decreased bile acids in bile so more cholesterol in bile increased formation of cholesterol containing gall stones
Fistulas and abscesses – enterovesical fistula (most common) increased incidence of UTI, fecaluria, pneumaturia
Enteroenteral fistula – bowel to bowel fistula
Enterocutaneous fistula – drainage of bowel matter near the anus and perianal abscess formation
Strictures – narrowing of ileocecal junction causing partial obstruction (small bowel obstruction)
Complications of Ulcerative Colitis
Colitis\ megacolon
increased pain, fever, white cell count
Severe malabsorption increased bloody stools and frequency
Colon becomes so inflamed it shuts down nerves and muscles causing massive decreases in motility causing increased dilation and pressure resulting in toxic megacolon
Toxic megacolon is if diameter is more than 6cm with fever, pain, leucocytosis. Increased risk of perforation
Increased colorectal cancer risk
Extraintestinal complications of IBD
Arthralgia –
Uveitis – red eye and eye pain
Skin lesions – pyoderma gangrenous or erythema nodosum
DVT PE (VTE) – hypercoagulabity of pt due to inflammation
Primary sclerosing cholangitis
When should you not do barium enema?
When suspecting toxic megacolon as increased risk of perforation
Tx of Crohn’s disease
Treat depending on severity and location.
Mild – moderate: 5-ASA (5aminosalicyclic acid or mesalazine) if colonic (rectal) -> if works continue use
Budesonide if ileal (oral)
Moderate – severe: PO corticosteroids – reduce inflam
maintain and reduce flair ups with antimetabolites 6-MP or AZA (mercaptopurine and azathioprine)
Severe\ refractory CD: (those with lots of complications, need to put them into remission asap)
IV steroids (methylprednisolone)
Anti – TNF agents (infliximab)
Anti – integrins (vedolizumab)
Anti – IL 12/23 (Ustekinumab)
Complication management
abscess\fistula\ strictures – surgery
Colonoscopy every 1-3yrs for colorectal cancer surveillance
Which drugs do we use to induce remission of Crohn’s disease?
5ASA
Steroids
Anti TNF agents
Which drugs do we use to maintain remission of Crohn’s?
5 ASA
antimetabolites (6-MP or azathioprine)
anti TNF agents
Anti integrins
Anti IL 12/23
