GIT pdf - حسن سالم

Lec 5:dr.hassan aljumaily
Inﬂammatory bowel diseases
UC and Crohn’s
protracted relapsing and remitting
course, usually extending over years.
A crucial distinction is that ulcerative
colitis

only involves the colon

, while

Crohn’s disease can involve

any part

of the GIT from mouth to anus.

Pathophysiology

Genetic:

1-Both CD and UC common in Ashkenazi Jews
2- High concordance in identical twins (40–50% CD;
20–25% UC)
3- UC and CD both associated with genetic variants at
HLA locus.
4-

HLA-DR 103

associated with severe UC

Environmental
• UC more common in non-smokers
• CD more common in smokers
• CD associated with high-reﬁned-sugar diet
• Appendicectomy protects against UC

Ulcerative colitis

-Proctitis

40–50%

,Left-sided colitis

30–40%

and

Extensive colitis

20%

- In long-standing pancolitis, the bowel can become

shortened

and post-inﬂammatory ‘

pseudopolyps’

-The inﬂammatory process is limited to

the mucosa

and spares the deeper layers of the bowel wall

,both

acute and chronic inﬂammatory cells inﬁltrate the
lamina propria and the crypts

(‘cryptitis

’). Crypt

abscesses are typical.
-

Dysplasia, nuclear atypia and increased mitotic rate,

may herald development of colon cancer.

Crohn’s disease

:most common site in order of frequency
1-terminal ileum and right side of colon
2-colon alone
3- terminal ileum alone
4-ileum and jejunum.
--

deep ulcers

which often appear as linear

ﬁssures; thus the mucosa between them is
described as ‘

cobblestone

’. These

may

penetrate

through the bowel wall to initiate

abscesses or ﬁstulae involving the bowel,
bladder, uterus, vagina and skin of the
perineum.

Clinical features

Ulcerative colitis:

-rectal bleeding with ,bloody diarrhoea.

-Emotional stress, intercurrent infection, gastroenteritis,

antibiotics or NSAID therapy may all provoke a relapse. - .

-Some patients pass frequent, small volume ﬂuid stools,

while others pass pellety stools due to constipation.

-assessment of severity depend on:

Daily bowel frequency , Blood in stools , Stool volume ,

Pulse ,Temperature ,Haemoglobin , ESR &

C-reactive protein ,Serum albumin , Abdominal X-ray and

Sigmoidoscopic ﬁnding

The Truelove–Witts

criteria for acute severe ulcerative

colitis are ≥ 6 bloody stools/24 hrs plus one or more of

anaemia, fever, tachycardia and high inﬂammatory markers

Crohn’s disease:

-abdominal pain, diarrhoea watery and does not contain

blood or mucus. and weight loss.

-Ileal Crohn’s disease

→intestinal obstruction.

-Weight loss because

they avoid food

, since eating

provokes pain also due to

malabsorption

, and some

patients present with features of fat, protein or vitamin

deﬁciencies.

-Crohn’s presents in an identical manner to ulcerative

colitis, but rectal sparing and the presence of perianal

disease are features which favour a diagnosis of Crohn’s

disease.

-other:

perianal disease

, Perianal skin tags, ﬁssures or ﬁstulae

are found in at least 50% of patients.

vomiting

from jejuna strictures

- severe

oral ulceration.

Differential diagnosis

1-Infective
-Bacterial •

Salmonella

•

Shigella

•

Campylobacter

jejuni

•

E. coli

O157 • Pseudomembranous colitis

-Viral • Herpes simplex proctitis •
Cytomegalovirus
Protozoal • Amoebiasis
Non-infective
• Ischaemic colitis
• Radiation proctitis
• Collagenous colitis
• Behçet’s disease
• NSAIDs
• Colonic carcinoma
• Diverticulitis

Complications

1-Life-threatening colonic inﬂammation:

Intoxic megacolontoxins pass freely across the
diseased mucosa into the portal and then systemic
circulation.
. An abdominal X-ray :transverse colon is dilated to
more than 6 cm

Haemorrhage

due to erosion of a major artery.

3-Fistulae

These are speciﬁc to Crohn’s disease.

Enteroenteric

ﬁstulae.

Enterovesical

ﬁstulation causes

recurrent urinary infections and pneumaturia.

enterovaginal ﬁstula

causes a faeculent vaginal

discharge.

4-Cancer

The risk of dysplasia and cancer increases with the duration

and extent of uncontrolled colonic inﬂammation..

Oral mesalazine

therapy reduces the risk of dysplasia and

neoplasia in ulcerative colitis.

Azathioprine

reduce the risk of colorectal cancer in ulcerative

colitis and Crohn’s colitis.

- surveillance programmes beginning

10 years

after diagnosis.

Targeted biopsies of areas that show abnormalities on

staining with indigo carmine or methylene blue increase the

chance of detecting dysplasia and this technique (termed

pancolonic chromo-endoscopy) has replaced colonoscopy

with random biopsies taken every 10 cm in screening for

malignancy

If high-grade dysplasia is found, panproctocolectomy is

usually recommended because of the high risk of colon

cancer.

Investigations

▲Blood:

1- anaemia resulting from bleeding or malabsorption of iron, folic

acid or vitamin B12.

2-Serum albumin concentration falls as a consequence of protein-

losing enteropathy, inﬂammatory disease or poor nutrition.

3- The ESR and CRP are elevated.

4-Faecal calproctectin

▲

Bacteriology

-stool microscopy, culture, blood cultures and serological tests

should be performed.

▲

Endoscopy

-Patients who present with diarrhoea plus raised inﬂammatory

markers or alarm features, such as weight loss, bleeding and

anaemia

In ulcerative colitis, there is loss of vascular pattern, granularity,

friability and contact bleeding,with or without ulceration.

In Crohn’s disease, patchy inﬂammation, with discrete, deep ulcers,

strictures and perianal disease (ﬁssures, ﬁstulae and skin tags), is

typically observed, often with rectal sparing.

▲

Radiology

Barium enema

is a less sensitive

2- barium follow-through

demonstrates affected areas of the

bowel as narrowed and ulcerated, often with multiple

strictures This has now largely been replaced by MRI

enterography

3- A plain abdominal X-ray

is essential in the management of

patients who present with severe active disease.

Dilatation of

the colon, mucosal oedema (thumb-printing) or evidence of

perforation

. In small bowel Crohn’s disease, there may be

evidence of intestinal obstruction or displacement of bowel

loops by a mass.

4-Ultrasound is a very powerful tool to detect small bowel

inﬂammation and stricture formation

5-The role of CT

in perforation or abscess formation

Management

. The key aims of medical therapy are
to:
• treat acute attacks (induce
remission)
• prevent relapses (maintain
remission)
• prevent bowel damage
• detect dysplasia and prevent
carcinoma
• select appropriate patients for
surgery

Aminosalicylates

(mesalazine)

Corticosteroids (prednisolone, hydrocortisone, budesonide)Anti-

inﬂammatory

Bisphosphonates are co-prescribed to prevent osteopenia

Thiopurines (azathioprine, mmunomodulation by inducing T-cell

MethotrexateAnti-inﬂammatory

Ciclosporin Suppresses T-cell expansion'Rescue' therapy to prevent

surgery in ulcerative colitis responding poorly to corticosteroids. No

value in CD

Anti-TNF antibodies (inﬂiximab and adalimumab)Suppress inﬂammation

and induce apoptosis of inﬂammatory cells :Moderately to severely

active Crohn's disease, especially ﬁstulating ;Severe active ulcerative

colitis.Anaphylactic reactions after multiple infusion

Contraindicated in the presence of infections; reactivation of

tuberculosis, increased risk of infections and malignancy

Antibiotics Antibacterial Useful in perianal Crohn's disease .

metronidazole

Antidiarrhoeal agents

(loperamide, lomotil)Reduce gut motility and small

bowel secretion improves anal function .Avoided in acute ﬂare-ups of

disease May precipitate colonic dilatation

♠Ulcerative colitis

1-Active proctitis.

suppository ± oral 5-

aminosalicylate (5-ASA). resistant disease

→corticosteroids and immunosuppressants.

2-Active left-sided or extensive ulcerative colitis.

mild to moderate :
- combination of oral and a topical 5-ASA preparation
-In patients who do not respond to this approach
within 2–4 weeks, steroid indicated.
-If corticosteroid resistance (lack of eﬃcacy) or in
patients who require high corticosteroid doses to
maintain control

→ immunosuppressive therapy with a

thiopurine should be introduced.

Severe ulcerative colitis

• Admission
• IVF and correction of electrolyte imbalance
• Transfusion if Hb < 10 g/dL
• IV methyl prednisolone or hydrocortisone
• AB until enteric infection excluded
• Nutritional support
• LMWH: prophylaxis of venous thromboembolism
• Avoidance of opiates and antidiarrhoeal agents
• Consider inﬂiximab or ciclosporin in stable patients
not responding to 3–5 days of corticosteroids

♠

Crohn’s disease

A-Induction of remission

Aminosalicylates and corticosteroids are both effective

and usually induce remission in active ileocolitis and colitis

Calcium and vitamin D

supplements.

enteral nutrition

with either an elemental

(constituent amino acids) or polymeric (liquid protein)
diet may induce remission.
4-In severe disease, induction therapy with an

anti-TNF

agent

(inﬂiximab and adalimumab) is appropriate,

unless there is abscess.
-

combination therapy with an anti-TNF antibody and a

thiopurine

is the most effective strategy for inducing

and maintaining remission

B-Maintenance therapy

thiopurines

(azathioprine and

mercaptopurine) Or methotrexate…

note : methotrexate is teratogenic.

Combination

therapy with an

immunosuppressant and an anti-TNF

antibody is the most effective strategy

but

costs

are high and there is an

increased risk of

serious adverse effects

stop smoking

C-Fistulae and perianal disease

Fistulae

often associated with sepsis.treat:Sx

-Corticosteroids are ineffective.
- For simple perianal disease,

metronidazole and/or

ciproﬂoxacin are ﬁrst-line therapies

Thiopurines

can be used in chronic disease but do not

usually result in ﬁstula healing.

Patients who are

intolerant of or resistant to thiopurines should be
treated with once-weekly methotrexate combined
with folic acid

Inﬂiximab and adalimumab

can heal ﬁstulae and

perianal disease in many patients and are indicated
when the measures described above have been
ineffective.

Indication of Sx:in UC
1-Impaired quality of life
• Loss of occupation or education
• Disruption of family life
2-Failure of medical therapy
• Dependence on oral corticosteroids
• Complications of drug therapy
3-Fulminant colitis
4-Disease complications unresponsive to
medical therapy • Arthritis • Pyoderma
gangrenosum
5-Colon cancer or severe dysplasia

♠

Crohn’s disease:

-The indications for surgery are similar to
those for ulcerative colitis.
-

Operations

are often necessary to deal with

ﬁstulae, abscesses and perianal disease, and
relieve small or large bowel obstruction.
- Incontrast to ulcerative colitis, surgery is not
curative and disease recurrence is the rule.
-The only method that has consistently been
shown to reduce post-operative recurrence is

smoking cessation