5.5. Intestinal Disease - Ulcerative Colitis (IBD)

Question 1

What is the Aetiology of Ulcerative Colitis?

Answer 1

This is unknown, but it is clear that there is an interaction between several co-factors

Question 2

What co-factors are thought to cause Ulcerative Colitis?

Answer 2

1. Genetic Susceptibility - This is a complex Polygenic Disease
2. Environmental Factors
3. Intestinal Microbiota - The number of Mucosal Adherent Bacteria is increased

Question 3

What are the Risk Factors which make up the Genetic Susceptibility to Ulcerative Colitis?

Answer 3

1. Family History - the largest independent risk factor
2. People with mutations of the (Chromosome 16) NOD2 gene - expressed on the Epithelial/Endothelial Cells, and Macrophages

Question 4

What are the Risk Factors which make up the Environmental Factors for the Susceptibility of Ulcerative Colitis?

Answer 4

1. NSAID’s
2. Nutritional Factors
3. Psychological Factors

Question 5

How are NSAID’s associated with the Aetiology of Ulcerative Colitis?

Answer 5

This is associated with the Onset and Flaring of the disease

Question 6

How is Nutrition associated with the Aetiology of Ulcerative Colitis?

Answer 6

1. Some foods are suggested to play a role but none have been proven
2. Breast feeding may provide protection against the developing within offspring

Question 7

How are Psychological Factors associated with the Aetiology of Ulcerative Colitis?

Answer 7

Chronic Stress / Depression increase relapses in patients

Question 8

What Environmental Factors appear to be “Protective” of Ulcerative Colitis?

Answer 8

1. Smoking

2. Having had an Appendectomy

Question 9

What are the Risk Factors which make up the Intestinal Microbiota for the Susceptibility of Ulcerative Colitis?

Answer 9

1. Bacterial Antigens
2. Defective Chemical Barrier
3. Imparied Mucosal Barrier
4. Butyrate

Question 10

How are Bacterial Antigens associated with the Aetiology of Ulcerative Colitis?

Answer 10

There is an increase of Bacteria which exert their influence by Ligands, which interact with Host-Pattern Receptors in Ulcerative Colitis

Question 11

How is a Defective Chemical Barrier associated with the Aetiology of Ulcerative Colitis?

Answer 11

Evidence suggests a decrease in Human Intestinal Defensin “Alpha-Defensin-1” (HD-1) can lead to Ulcerative Colitis

Question 12

How is a Impaired Mucosal Barrier associated with the Aetiology of Ulcerative Colitis?

Answer 12

This can explain the presence of unusual and potentially pathogenic bacteria, which can lead to Ulcerative Colitis

Question 13

What is Butyrate?

Answer 13

A type of fatty acid which helps with Intestinal Function

Question 14

How is a Butyrate associated with the Aetiology of Ulcerative Colitis?

Answer 14

1. A Sulphate-Producing Bacteria which increases Luminal Levels of Hydrogen Sulphide
2. This decreases Butyrate Oxidation in the Colonic Mucosa
3. This leads to Mucosal Inflammation which can precede Ulcerative Colitis

Question 15

How does Ulcerative Colitis spread?

Answer 15

Distally to Proximally

Question 16

What areas can Ulcerative Colitis effect?

From Best to Worst case scenario

Answer 16

1. The Rectum alone (Proctitis)
2. This can then extend to effect the Sigmoid and Descending Colon (Left Sided Colitis)
3. This can then extend to involve the whole colon (Extensive / Total Colitis)
4. There can also be inflammation on the Terminal Ileum (Backwash Ileitis)

Question 17

Why does the inflammation in Ulcerative Colitis occur?

Answer 17

Due to the Mucosal Immune System exerting an inappropriate Response to Luminal Antigens (e.g. Bacteria). These Bacteria may enter into the Mucosa via a Leaky Epithelium

Question 18

What are the Macroscopic Changes which occur in Ulcerative Colitis?

Answer 18

1. Reddened, Inflamed Mucosa which Bleeds Easily (Friability)
2. Inflammatory (Pseudo-)Polyps

Question 19

What are Inflammatory (Pseudo-)Polyps?

Answer 19

These are present in sever disease, where there is extensive Ulceration with the Adjacent Mucosa appearing as Inflammatory

Question 20

What are the Microscopic Changes which occur in Ulcerative Colitis?

Answer 20

1. Chronic Inflammatory Cell Infiltrates in the Lamina Propria
2. Lymphoid Hyperplasia
3. Grypt Abscesses
4. Goblet Cell Depletion

Question 21

What are the Clinical Features of Ulcerative Colitis?

Answer 21

1. Diarrhoea with Blood
2. Constitutional Symptoms (Mailaise, Fever, Lethargy)
3. Nausea and Vomiting
4. Anorexia / Weight Loss
5. Aphthous Ulceration of the Anus and Mouth only
6. Lower Abdominal Discomfort

Question 22

What investigations are necessary for Ulcerative Colitis?

Answer 22

1. Colonoscopy
2. Abdominal Ultrasound / X-Ray / CT scan
3. Stool Cultures and Clostridium Difficile Toxin
4. Blood Tests

Question 23

What is the purpose of the Colonoscopy?

Answer 23

To view the inside of the Colon, looking for Macroscopic Changes and to see how far the ulceration reaches

Question 24

What is the purpose of the Abdominal Ultrasound / X-Ray / CT scan?

Answer 24

To view the outside of the Colon and to loo

Question 25

What is the Stool Culture looking for?

Answer 25

1. Clostridium Difficile Toxin assay when Diarrhoea is present 2. Faecal Calprotectin and Lactoferrin are raised in Active Colonic Disease

Question 26

What are the Blood Tests looking for?

Answer 26

1. Iron Deficiency Anaemia with a raised White Cell Count and platelets 2. Serum Inflammatory Markers (CRP and ESR) are normally raised 3. Liver Biochemistry may be abnormal due to the potential decrease in re-absorption of Bile 4. pANCA is normally positive (it is normally negative in Crohn's)

Question 27

What is the treatment of Ulcerative Colitis?

Answer 27

1. 5-aminosalicylic acid (5-ASA), from Oral - Rectal - Topical administration, for induction and maintenance of Remission 2. Oral Prednisolone - to initiate remission 3. Azathioprine - a steroid sparing agent used over a longer period of time 4. Anti-TNF antibodies (Infliximab) 5. Proctocolectomy - the surgical removal of the effected area

Question 28

What is the term given to Colitis which cannot be distinguished between Crohn's Disease and Ulcerative Colitis origin?

Answer 28

Colitis of Unknown Type and Aetiology (CUTE)