Inflammatory Bowel Disease

- a clinical perspective

Crohns Symptoms and signs • depend on the extent and severity of inflammation • Symptoms

– onset of symptoms is typically insidious – the clinical course is characterized by recurring episodes of symptomatic disease

interspersed with periods of remission– Abdominal pain and diarrhoea are the most typical symptoms– Unlike ulcerative colitis, diarrhoea is often non-bloody– Fever and weight loss are common in active disease.

• Signs – abdominal tenderness, most classically in the right lower quadrant– An abdominal mass may be palpable. – wasting and cachexia indicate significant malnutrition– Typical symptoms of small bowel obstruction eg. distension, may be present in stenosing

disease– Perianal and cutaneous fistulae are readily identified on a careful perineal and skin

examination.

Note: involvement of the rectum will bring about bloody diarrhoea – however this is not considered common with the terminal ileum the preferential site.

Ulcerative Colitis- Symptoms and signs

• depend on the extent and severity of inflammation • Signs

– Unlike Crohn disease, ulcerative colitis is frequently acute or subacute in onset– Like Crohn disease, the subsequent clinical course is one of recurring episodes

of symptomatic disease interspersed with episodes of relative (or complete) quiescence.

– Overt rectal bleeding and tenesmus are virtually universally present and may be the only symptoms in patients with proctitis alone

– diarrhoea, cramps, urgency and abdominal pain are more frequent complaints.

– Nausea, fever, weight loss indicate severe disease.

• Signs – mild abdominal tenderness, often most localized in the hypogastrium or left

lower quadrant. • Digital rectal examination may disclose visible red blood. • As with Crohn disease, signs of malnutrition may be evident. • Severe tenderness, fever, or tachycardia in serious disease

Complications CROHNS• As the inflammation in Crohn disease is typically transmural, this frequently leads to complications of

penetrating and stenosing disease, including perforation, abscess, fistulae, and obstruction• Active small bowel disease or extensive small bowel resection may lead to malabsorption• Deficiencies in iron, folate, vitamin B12, and fat-soluble vitamins (A, D, E, and K) are common, with resulting

complications including anaemia and osteoporosis• Because Crohn disease has a predilection for the ileum, bile salt reabsorption is frequently compromised bile-

salt–induced diarrhoea (responsive to bile-acid sequestrants), fat maldigestion and steatorrhea• Extensive small bowel disease or resection can also lead to short gut syndrome, with protein-calorie and

micronutrient deficiency and dependence on parenteral nutrition• Malabsorption of fatty acids renal calculi. Calcium readily binds unabsorbed fatty acids, allowing oxalate to be

taken up by the bowel in greater quantity. Subsequent renal excretion of this excess oxalate promotes the precipitation of calcium oxalate calculi.

• Increased risk of colorectal cancer, adenocarcinomas of stomach and cholangiocarcinoma

UC• Severe haemorrhage is more common • Toxic megacolon with subsequent infarction and perforation while still uncommon, is more likely• Risk of colorectal cancer (CRC) is significantly increased (also slightly increased in Crohn’s)

IBD may also cause extraintestinal complications – The diagnosis of PSC may precede or follow that of IBD; symptoms and signs may arise years after colectomy. – Of the dermatologic considerations, erythema nodosum is most common. Pyoderma gangrenosum is rarer and

more worrisome. – Uveitis is of special concern, as it can lead to blindness if untreated. Patients with eye pain, redness, and visual

disturbance require urgent ophthalmologic evaluation (mainly associated with colonic)

Extraintestinal SignsTable 3–3. Common extraintestinal manifestations of inflammatory bowel disease.

System or Site 

Manifestation 

Hepatobiliary Primary sclerosing cholangitis

Cholangiocarcinoma

Gallstones

Dermatologic Erythema nodosum

Pyoderma gangrenosum

Sweet syndrome

Oral Aphthous ulceration

Ocular Episcleritis

Uveitis/iritis

Musculoskeletal Enteropathic arthropathy

Sacroiliitis

Ankylosing spondylitis

Osteopenia/osteoporosis

Hematologic Thromboembolic disease

Prognosis

• relapsing illnesses

• 75% of patients with Crohn disease can expect to have surgery over the course of the illness

• The majority of patients with ulcerative colitis can be managed using medical therapy with the prospect of surgery reaching 25%

• No single symptom, physical finding, or test result can diagnose IBD. The diagnosis of both Crohn disease and ulcerative colitis is a clinical one, based on compatible patient history; physical examination; and laboratory, radiographic, endoscopic, and histological findings. 

Quiz

Obstruction

1. a) Name the major causes of intestinal obstruction? AND

b) What are the clinical manifestations of intestinal obstruction?

• Collectively, hernias, intestinal adhesions, intussusception, and volvulus account for 80% of mechanical obstructions

• tumors and infarction account for only about 10% to 15% of small bowel obstructions.

• The clinical manifestations of intestinal obstruction include abdominal pain and distention, vomiting, and constipation

Congenital

2 a) What is the underlying abnormality in Hirschsprung's disease? AND

b) How does it present?

• a distal intestinal segment that lacks both the Meissner submucosal and the Auerbach myenteric plexus ("aganglionosis")

• Coordinated peristaltic contractions are absent and functional obstruction occurs, resulting in dilation proximal to the affected segment.

• Patients typically present neonatally, often with a failure to pass meconium in the immediate postnatal period

Acquired

3 a) Diverticula can be found anywhere in the intestinal tract, but the colon (particularly the sigmoid) is by far the commonest site. WHY?

b) The disease is generally acknowledge to result from a diet deficient in fibre. What is the mechanism?

• Nerves and blood vessels penetrate the inner circular muscle layer of the muscularis propria, forming weak points.

• In the rest of the intestines the gaps are reinforced by the external longitudinal layer of the muscularis propria.

• In the colon, the longitudinal layer is gathered up to form the taeniae coli, thus cant provide this protection and the mucosa buldges into the subserosa

• Why the sigmoid?- sigmoid motility is particularly sensitive to bulk of stool

• Low fibre = low bulk of colonic content = increased intra-luminal pressure generated to push content along= pressure pushes mucosa into the wall

4 a) Haemorrhoids- Which vessels are affected?

b) How do they present?

• Haemorrhoids are varicosities resulting from dilatation of the internal haemorrhoidal/rectal venous plexus

• Haemorrhoids present with rectal bleeding as streaks of blood on the outside of the stool

5. List some infective causes of bloody diarrhoea.

• Campylobacter spp.

• Shigellosis

• Salmonellosis

• Enteric (typhoid) fever

• Escherichia coli (Enteroinvasive (EIEC) Enterohemorrhagic (EHEC) )

6 a) What is the pathogenesis of pseudomembranous colitis?

b) How is it diagnosed?

• Disruption of normal colonic flora by antibiotics, allows C difficile overgrowth

• Immunoassay for c. difficile toxin in stool

7 a) What is the diagnostic criteria of Irritable Bowel Syndrome (IBS)?

b) What are the pathological features?

Diagnosis of exclusion. 3 Criteria– Abdominal pain or discomfort for atleast

3days/month for 3 months– Improvement with defecation– A change in stool frequency or form

• Despite very real symptoms the gross and microscopic appearance is normal.

8. Match the Number to the (most) correct letter

A. Fistula 1. herniations of mucosa in intestinal wall B. Fissure 2. cavity or blind-ended channelC. Sinus 3. loss of superficial layer of mucosal surfaceD. Ulcer 4. abnormal, inflammatory connections

between two hollow structures E. Erosion 5. penetrating ulcers forming grooves or

cleft F. Polyp 6. mass that protudes into lumen of gut G. Diverticula 7. full thickness loss of the mucosa

A. 4

B. 5

C. 2

D. 7

E. 3

F. 6

G. 1

9. IBD is an idiopathic disorder and the responsible processes are only beginning to be understood. Which of the following is not thought to be involved in the pathogenesis of IBD?

a) genetics

b) inappropriate mucosal immune response

c) intestinal microbiota

d) intestinal epithelial dysfunction

e) autoimmunity

e)

• neither Crohn disease nor ulcerative colitis is thought to be an autoimmune disease

10. The incidence of IBD is low, however the prevalence is high. What does this mean? What factors of the disease contribute to this?

• Means not alot of people are getting diagnosed, but a lot of people living with IBD.

• due to – presenting in relatively young people– Long course of disease- normally don’t die

from IBD itself…

11. The incidence in developing countries is on the rise. What is the

hypothesis behind this??

• Hygiene Hypothesis:– Improved food storage conditions and

decreased food contaminations reduced frequency of enteric infections inadequate development of regulatory processes to limit mucosal immune responses = pathogens that should be self-limiting trigger overwhelming immune response and chronic inflammatory disease insusceptible hosts

12. Decide which of the following signs/symptoms/complications is

more likely to be related to Crohns/ UC

• Bloody diarrhoea• R lower quadrant abdominal pain• L lower quadrant abdominal pain• Feeling of incomplete emptying of the

rectum and urgency• Rectovaginal fistula• Toxic megacolon• Fever

• Bloody diarrhoea (UC or rectal involvement of C)• R lower quadrant abdominal pain (C)• L lower quadrant abdominal pain (UC)• Feeling of incomplete emptying of the rectum

and urgency (UC)• Rectovaginal fistula (C)• Toxic megacolon (UC)• Fever – either acute, or exacerbations

13. Name 3 conditions that can lead to haemorrhoids?

• Pregnancy- uterus compresses vena cava

• Portal Hypertension

• Constipation- straining

14. What are the mechanisms by which bacteria cause diarrhoea?

• Toxins- ingestion of preformed toxins or toxigenic organism

• Mucosal adherence

• Mucosal invasion

15. What are carcinoid tumours and what are the symptoms of carcinoid

syndrome??

• A diverse group of tumours of enterochromaffin cell origin, by definition capable of producing serotonin. May (also?) secrete gastrin, insulin, glucagon

• Bronchoconstriction, flushing, diarrhoea and CCF

16. When does diarrhoea warrant investigation?

• I’ll patient- fever etc.

• Recently returned traveller

• chronic