IBD - Crohn's Disease Flashcards
What is the aetiology of IBD and Crohns?
- Largely unknown
- An interaction between luminal microbial antigens, genetic susceptibility, immune response and environmental triggers
What is Crohn’s disease characterized by?
- Dysfunctional regulatory T-cells which normally control pro-inflammatory cytokine releases.
- If activated antigen presenting cells and lymphocytes are allowed to secrete these pro-inflammatory cytokines, then tissue damage may result from prolonged inflammation
What is a key player in crohn’s disease?
TNF alpha
What is the prevalence of IBD? Is CD and UC more common?
- 0.67%
- CD slightly more common (129,000) compared to UC (104,000)
Whats the difference between IBS and IBD?
IBD has presence of ulcerations
-May share similar symptoms
What is the prevalence of crohn’s disease in Canada?
319 per 100,000
In CD there are more females (T/F)
T
In UC, there are slightly more males, however we don’t know why
What are the common characteristics of IBD? (3)
- Affects all levels of the GIT
- Often onset in youth
- 30-50% of people have the colon affected
Which parts of the colon are often affected in IBD?
- Ileocolonic (50-60%)
- Crohn’s colitis (10-30%)
(T/F) Crohn’s disease affects only the large intestine
F
Can be the small or large intestine, often “patches” throughout
What is the difference between ileocolic and colon originates crohn’s disease?
- ileocolic will present with affected arears in the terminal ileum, and patches throughout the colon
- Colon means the patches are distributed throughout the colon only
Where is the affected area in recto-sigmoid crohns?
- In the terminal sigmoid colon and rectum
- Continuous and not patchy
When may UC be misdiagnosed for chron’s?
If it’s initial presentation is in the colon, and is patchy
When may crohn’s be a misdiagnosis of UC?
When it is present in the colon and not yet pathcy
What is the presentation of UC?
-Continuous, not patchy throughout the colon to anus
What is the Montreal Disease Activity Score?
Allows us to define UC by the extent of affected area. Considers 3 subgroups.
What does E1 represents in the MDAS?
- Ulcerative proctitis
- Involvement limited to the rectum (i.e, proximal extend of inflammation is distal to the rectosigmoid junction)
What does E2 represent in the MDAS?
- Left sided UC, or distal UC
- Involvement limited to the portion of the colorectum distal to the splenic flexure
What does E3 represent in the MDAS?
- Extensive US, or pan-colitis
- Involvement extents proximal to the splenic flexure
What is the significance of tool required to diagnose IBD?
-There is often lengthly preparation to undergo these diagnoses, such as fasting, and often patients with IBD are malnourished at baseline
Preparation for endoscopy?
- 8 hr NPO
- May exacerbate malnutrition
Discuss the 2-3 day preparation in order to undergo a colonoscopy
1) Obtain bowel preparation solution at least 2 days before the test
2) 1 day before test; clear liquids all dat, Then, from 6-8pm drink 2L of any PEG-based solution
3) Dat of test, no solid food , and 4 hour before appointment, drink remaining 2L of PEG based solution
4) Stop drinking all liquids including water 2 h before the test
What is the PEG solution?
- PIC-SALAX
- Contents are not absorbed, and will function to “clean the bowel” so that we can observe ulcerations upon colonoscopy
Overall preparation guielines for colonoscopy on Pico-Salax?
- No fibre 3 days prior
- Day prior can have breakfast and then clear fluid only plus lavage
When assessing a patient with potential IBD, what do we need to investigate?
- Is it UC or Crohn’s? Where is the inflammation? (Recall that Crohn’s can go from anus to mouth
- Are there stricture, ulcers? How deep are the strictures?
- What is the patient currently able to eat?
- Has there been weight-loss?
- What medication is she on?
A1?
16 years or younger
A2?
17-40 years
A3?
Over 40 years
L1?
Terminal ileum
L2?
Colon
L3?
Ileocolon
L4?
Upper GI
B1?
Non-stricturing, non-penetrating
B2?
Stricturing
B3?
Penetrating
B1 or 2 or 3 with p?
+ perianal
In UC, what do the ulcerations on the colon lead to?
- Toxic megacolin
- A thin, ulcerated colon which has complete lack of the strong-muscular walls
- People can due for this as the thin walls can perforate and cause sepsis
What is the solution for toxic megacolon?
- Take out the large intestine
- Likely have an ostomy
What does Crohn’s disease primarily present with?
- Ulcers, fistulas, strictures and obstructions
- Makes the lumen and peristalsis less functional and flexible
What is transmural?
- All the way through
- Through the mucosa, submucosa and musculature into the peritoneal cavity (high risk of sepsis)
- Can transverse both circular an longitudinal muscle
What is the mesentery?
A set of tissues that attaches the intestines to the posterior abdominal wall in humans and is formed by the double fold of peritoneum.
-Helps lead nutrients to the surrounding vascular system
What happens when the mesentery is thickened?
-Will have difficulties in supplying nutrients from the villi, and will also not transport nutrients to the liver (bidirectional) may not have enough oxygen
What is commonly observed in the affected area during IBD?
-Enlarged lymph nodes
What is an aphthoid ulcer?
-Ulcer over payer’s path’
-Ulcer over immune spots
and similar to canker sores
What are skip lesions?
- Patchy distribution of inflammation
- Recall the inflammation is normally continuous and contained to the colon in UC
What is a fissure?
-Deep cleft, slit or linear ulcers
What is a fistula?
An abnormal passage from a hollow organ to surface of another organ stricture; narrowing of hollow organ can ensure, causing scaring and fibrosis
What are abscesses?
a swollen area within body tissue, containing an accumulation of pus.
What are granuloma?
When tissue in an organ becomes inflamed — often in response to an infection — groups of cells called histiocytes cluster to form little nodules. May become calcified and hardened over time.
What type of IBD is at higher risk of fistula development?
Crohn’s
What else is consistent with IBD pathology?
- Perianal disease (when complication occur in the anus/rectum)
- Inflamed mucosa with adjacent normal tissue (recall skip lesions)
- Perianal skin tags
What are common clinical presentations of crohns?
- “Cobble-stoning” of intestinal lumen
- Marked thickening of bowel wall
- fat wrapping around outside of GI tract (due to high inflammatory state)
- Deep fissures
- -> MAJOR impacts on absorption
What are common clinical presentations of ulcerative colitis?
-Extremely thin, ulcerated wall
-“surviving” mucosa is known as pseudopolyps
-Loss of haustra
(the sacs)
—> MAJOR impact on absorption
What are the general clinical features of IBD?
- Skip lesions
- Thickened bowel wall
- Stricture formation
- Decreased brush-border lactase
- Diminished serum folate
- Reduce dietary intake (to avoid symptoms)
Which clinical features are conducive to malabsorption?
- Skip lesions
- Decreased brush border lactase
Which clinical features are conducive to obstruction?
- Thickening of bowel wall
- Stricture formation
(T/F) Due to decreased brush-border lactase, IBD patients must eliminate milk intake
- Not necessarily
- If tolerated, include in diet
- Important source of energy and protein
- Recall that patient likely malnourished at baseline, and if on corticosteroids even more so
If we must eliminate lactose from diet, what could be a compromise?
- Consider lactase enzyme supplement or lactose-free products to avoid omission of high protein high energy foods
- People with IBD are often already at increased risk of osteoporosis
What are the general clinical manifestations of IBD?
- Abdominal pain, bloody diarrhea, tenesmus
- Febrile, tachycardia
- CRP and WBC elevated
- Weight loss
What is tenesmus? What may it be caused by?
- The feeling of needing to pass stools even if there are none
- May be caused by strictures
What happens when people are tachychardic?
They often don’t sleep well
What is common in IBD?
- Anemia is very common
- Must determine whether IDA or AOCD (as both are likely)
What may indicate IDA?
- High CRP
- Low/normal Serum Ferritin
- Low HmG, low HcT
- Normal hydration status
- Historical low PO intake
What may indicated AOCD?
- High CRP
- HIGH serum ferritin (+APP)
- Low HmG, low Hct
- Normal Hydration status
What may low or normal WBC and CRP indicate?
That “inflammation” is still occurring, but managed by corticosteroids
-Consider when interpreting AOCD and IDA
Why do we need to make sure we interpret AOCD and IDA appropriately
- As we don’t want to unnecessarily provide an iron supplement as they can be irritating and cause constipation
- On the other hand, if they are really IDA this must be addressed as there is recurring blood loss and we want to avoid further decline in nutritional state
Common characteristics of small intestine crohn’s in the adult?
- Obstructive in nature (require Sx)
- Pain when eating
- Palpitation causes pain in LRQ
- Anorexia/diarrhea
- Malabsorption, including lactose intolerance
Which type of IBS has a high incidence of fistula formation?
-Ileocolonic disease
What is located in the LRQ?
Ileocolonic area, likely ileocolonic disease