Gastroenterology Flashcards
What are the two idiopathic chronic inflammatory diseases?
- Ulcerative colitis
- Crohn’s disease
When theres an overlap between ulcerative colitis and Crohn’s disease, what is this termed?
Indeterminate colitis
What is the clinical presentation of Crohn’s disease?
- abdominal pain
- diarrhoea
- peri-anal disease
What is the clinical presentation of ulcerative colitis?
- diarrhoea & bleeding
What three factors are involved in the pathogenesis of IBD?
- Genetic predisposition
- Mucosal immune system
- Environmental triggers
What is the name of a particular disease susceptibility gene involved in IBD?
NOD2/CARD15
What is the specific function of gene NOD2/CARD15?
Encodes a protein involved in bacterial recognition
Crohn’s disease is mediated by what cells?
Type 1 T helper (Th1) cells
Ulcerative colitis is mediated by what cells?
Mixed:
- type 1 T helper (Th1) cells
- type 2 T helper (Th2) cells
- natural killer T cells
What effects does smoking have on Crohn’s disease and ulcerative colitis?
- Aggravates Crohn’s disease
- Protects against ulcerative colitis
What medication should not be used in the case of IBD, as it can trigger a flare up?
NSAIDS
What part/s of the bowel does ulcerative colitis effect?
Colon (specifically the rectum)
What are the terms given for the three different extents of ulcerative colitis within the large intestine?
- Proctitis
- Left-sided colitis
- Pancolitis
What is meant by Proctitis?
Inflammation of the lining of the rectum
What is meant by left-sided colitis?
Inflammation extending from the rectum through the sigmoid and descending portions of the colon
What is meant by Pancolitis?
This is a form of ulcerative colitis that effects the entire large intestine
What are common symptoms of ulcerative colitis?
- diarrhoea + bleeding
- increased bowel frequency
- tenesmus (feeling of needing to go to toilet)
- Incontinence
- lower abdominal pain
How would you categorise severe ulcerative colitis?
> 6 bloody stools/24 hour period + 1 or more of:
- fever
- tachycardia
- anaemia
- elevated erythrocyte levels
What components would you expect to see in blood in a patient with ulcerative colitis?
- C-reactive protein (CRP)
- albumin
- platelets
What is the purpose of a colonoscopy?
This maps and assesses the extent of the colon involved in disease process
In an endoscopy, what signs would indicate active inflammation?
- loss of vessel pattern
- granular mucosa
- contact bleeding
True or false, ulcerative colitis affects the sbumcosual layers of cells?
False
What is the incidence of Crohn’s disease?
5 per 100,000/ year
What is a skip lesion?
Where there is an area of inflamed tissue, with area of normal tissue in front and behind
What is transmural inflammation?
Where the bowel wall thickens and in some cases the lumen narrow
What determines the symptoms of Crohn’s disease?
Determined by the site of the disease
What are the symptoms of Crohn’s disease in the small intestine?
- abdominal cramps
- diarrhoea
- weight loss
What are the symptoms of Crohn’s disease in the colon?
- Abdominal cramps
- diarrhoea with blood
- weight loss
What are the symptoms of Crohn’s disease in the mouth?
- angular chelitis
- Painful ulcers
- swollen lips
What are the symptoms of Crohn’s disease in the anus?
- Peri-anal pain
- Abscess
What is a characteristic feature of the large intestine wall in Crohn’s disease?
“Cobble stoning” effect
What are the three therapeutic strategies for IBD?
- lifestyle advice
- drugs
- surgery
What type of diet should you maintain if you have Crohn’s disease?
- low residue (fibre) diet
- elemental diet (e.g. modulen- has anti-inflammatory properties)
- strict gut rest (e.g. parenteral nutrition)
What medication should be used to treat acute flare ups of ulcerative colitis?
Steroids
What medication should be used to treat acute flare ups of Crohn’s disease?
Steroids
What medication/s should be used to treat chronic ulcerative colitis?
- mesalazine (5-ASA)
- immunosuppressants
- biologics
What medication/s should be used to treat Crohn’s disease?
- immunosuppressants
- biologics
Give an example of a corticosteroid given by IV to treat IBD.
Methylprednisolone/ hydrocortisone
Give an example of a corticosteroid given by orally or topically to treat IBD.
Prednisolone
What immunosuppressive medication is usually first line for treating Crohn’s disease and ulcerative colitis?
azathioprine
What is anti-TNF therapy?
Interferes with action of protein TNF which is overactive in the body in people with inflammatory disease
What is vedolizumab and its action?
It is a gut-selective integrin blocker. It blocks integrin which stops white blood cells entering the gut and this reduces inflammation
When would surgery be the best option for an individual with IBD?
In an emergency where there is failure to respond to medical therapy, small bowel obstruction, abscess or fistulae
Name the 5 therapies used for Crohn’s disease and/or ulcerative colitis.
- steroids
- 5-ASA
- immunosuppressives
- biologics
- JAK inhibitors
Name the three significant GI diseases that can occur due to malabsorption?
- Pernicious anaemia
- Coeliac disease
- Crohn’s disease
How do antacids function?
They are alkalis which form a salt with the gastric acid in GI tract and therfore neutralise its effect on tissues
What are the three main triggers which make parietal cells in the stomach produce acid?
- Acetylcholine
- Gastrin
- Histamine
How can acetylcholine be reduced?
By reducing the vagus nerve stimulation to the stomach, this can be done surgically by cutting the nerve
How can histamine production be reduced?
Using H2 receptor blockers
What drugs directly inhibit the release of acid?
Proton pump inhibitors
What is the action of H2 receptor antagonists?
Reduce acid production by preventing histamine activation of acid production
Name a H2 receptor which is safe for clinical use and licensed for over the counter sale?
Ranitidine
Name an example of a commonly used proton pump inhibitor
Omeprazole
Give three examples of oesophageal disorders
- Dysphagia
- Fibrosis (scleroderma or acid related)
- neuromuscular dysfunction (e.g. Parkinson’s)
Define scleroderma
Where elastic tissue is replaced by fibrous tissue
What is GORD?
Chronic irritation due to repeated acid reflux into the oesophagus
What is achalasia?
Where the nerve supply to the oesophagus does not form properly
What is functional dysphagia?
When anxiety causes loss of normal control of oesophageal function
What is dysmotility Dysphagia?
Where fibrous tissue replaces muscle tissue
What might cause Dysphagia in regards to surrounding structures?
Compression of the oesophagus by surrounding structures
What are the three main causes of GORD?
- defective lower oesophageal sphincter
- impaired lower clearing (not emptying properly into stomach)
- impaired gastric emptying
What are the effects/consequneces of GORD?
- ulceration
- inflammation
- metaplasia
- Barrett’s oesophagitis ( potentially malignant)
What cancer can result from Barrett’s oesophagitis?
Adenocarcinoma
What are the 4 main signs and symptoms of GORD?
- epigastric burning
- dysphagia
- GI bleeding
- severe pain (oesophageal muscle spasm)
What is a hiatus hernia?
When part of the stomach is in the thorax (chest)
What is peptic ulcer disease?
Where there are open sores or raw areas in the lining of the stomach or intestine
What are the causes of peptic ulcer disease?
- high acid secretion (duodenal)
- normal acid secretion (stomach)
- drugs (NSAIDS, steroids)
How can peptic ulcers cause significant bleeding?
If they erode through to an artery
What bacteria will cause loss of stomach mucosal barrier and by doing so allows the normal level of acid to reach the gastric wall and cause peptic ulceration?
Helicobacter pylori
What can the effects of helicobacter pylori result in?
- gastric ulcers
- chronic gastric wall inflammation (lymphoma of the stomach)
What triple therapy is used to eliminate helicobacter pylori?
- 2 antibiotics: usually amoxicillin and metronidazole
- 1 proton pump inhibitor: e.g. omeprazole
What are the possible signs/ symptoms of PUD?
- can be asymptomatic
- can have epigastric burning pain
What investigations can be carried out for suspected PUD?
- endoscopy
- radiology: barium meal
- anaemia: faecal occult blood test (FOB’s)
- H.pylori testing: breath, antibodies, mucosa
What are the local complications of PUD?
- perforation
- haemorrhage
- stricture
- malignancy
What are the systemic complications of PUD?
Anaemia due to loss of haemoglobin
What surgical treatments can be used for PUD?
- endoscopy
- surgical repair (gastrectomy)
- vagotomy
What is a vagotomy?
A surgical procedure which reduces acid secretion by dividing the vagus nerve branches to the stomach
What are the two types of PUD surgery called?
Bilroth 1 and bilroth 2
What happens during bilroth 1 surgery?
Allowed excision of part of the stomach containing the ulcers (usually the distal part of the stomach) and an anastomosis of the duodenum to the remaining part of the stomach. This makes the stomach smaller, which makes the diet reduced but allows a good flow from the stomach to the duodenum.
What is the disadvantage of bilroth 1 surgery?
There is not a sphincter present and therefore food tends to flow fairly freely into the duodenum and this can cause some problems
What happens during bilroth 2 surgery?
Allowed excision of part of the stomach containing the ulcers and an anastomosis of the duodenum to the remaining part of the stomach ( but much further down in the duodenum than in bilroth surgery 1)
Name 3 small bowel diseases
- Coeliac disease
- Pernicious anaemia
- Crohn’s disease
What area of the bowel is normally affected by peptic ulcer disease?
Duodenum
How can tumours develop from small bowel diseases?
Inflammatory changes can take place at a low level over many years leading to a lymphoma
What disease is characterised by sensitivity to alpha-gliaden component of Gluten?
Coeliac disease
What are the main food groups that gluten is found in?
Wheat, barley, spelt, rye, kaput, oats
What are the aetiology’s of coeliac disease?
- genetic
- environmental triggers
- consumption of gluten
- T lymphocytes damage mucosal tissues
- villus atrophy
How does coeliac disease result in the destruction of villus tissue?
The gluten alpha-gliaden component is passed through the bowel wall and an immune reaction develops. This produces antibodies and T cells which cause damage to the villus tissue in the jejunum.
What are the consequences of acute inflammation changes which take place due to coeliac disease?
- villus atrophy, with loss of projections and significant reduction in surface area available for food absorption
How is it easier to diagnose coeliac disease in a child compared to an adult?
It is more obvious as the malabsorption will effect the child’s ability to grow properly
What are the general symptoms associated with coeliac disease?
- weight loss
- lack of energy
- weakness
- abdominal pain/swelling
- diarrhoea
- steatorrhoea
- dysphagia
What are the oral symptoms of coeliac disease?
- oral aphthae (ulceration)
- tongue papillary loss
What are the typical malabsorption issues associated with coeliac disease?
Deficiencies in :
- iron
- folate
- vitamin B12
- fat
What syndrome can deficiency in iron lead to which can cause issues with the pharynx such as dysphagia?
Plumber Vincents syndrome (PVS)
What are the 4 investigations for coeliac disease?
- autoantibody test
- jejunal biopsy
- faecal fat
- Haematinics blood test
What are haematinics? Give examples
Substances that are essential as components in blood. E.g. folic acid, B12, folate
What levels of faecal fat would you expect to find in an individual with coeliac disease and why?
Increased levels due to malabsorption
What is the auto-antibody test used for coeliac disease investigation?
- serum transglutaminase (TTG)
If you have a positive TTG result, what does this indicate about a patient having coeliac disease?
The patient may or may not have coeliac disease
If you have a negative TTG result, what does this indicate about a patient having coeliac disease?
The patient does not have coeliac disease
What is the best way to manage coeliac disease?
Having a gluten free diet
What are the three advantages of a gluten free diet for a coeliac patient?
- Reversal of jejunal atrophy
- Improved well being
- Reduced risk of lymphoma
What skin disease is coeliac disease associated with?
Dermatitis herpetiformis
Why does dermatitis herpetiformis occur?
Due to granular IgA deposition in the skin and mucosal tissue
What characterises dermatitis herpetiformis?
Itchy blisters- usually over the shoulders but can be widespread, can also affect oral mucosa
What screening tool is used when patients present with oral aphthous ulcers and for what purpose?
Screened by haematinic assays to detect deficiencies
What result from haematinic assay screening would suggest malabsorption and potential coeliac disease?
Folate, or combined ferritin & folate deficiency
What disease is caused by vitamin B12 deficiency?
Pernicious anaemia
What protein, made in the stomach helps the intestines absorb vitamin B12?
Intrinsic factor (IF)
What group of individuals are most prone to vitamin B12 deficiency? And why?
Vegans, because B12 is present in food such as dairy products and meat.
What is the only B12 absorption site in the bowel?
Discrete area of the terminal ileum
What 4 factors can cause pernicious anaemia?
- Lack of vitamin B12 in diet
- Disease of gastric parietal cells
- Inflammatory bowel disease of terminal ileum (Crohn’s disease)
- Bowel cancer at ileo-coecal junction
What can be a barrier for some individuals when they require vitamin B12 supplements due to a deficiency?
Vitamin B12 supplements are usually made from animal products, can be an issue for vegans.
What medical treatment can be given for B12 deficiency if GI absorption is not possible?
IM injections of vitamin B12 every month for 3 months to restore patients stores
What can be severe consequences of B12 deficiency?
- neuorlogical damage
- affect bone marrow production for red blood cells
What is another word for bowl cancer?
Colonic cancer
What cancer of the large bowel is the second most common malignancy in the western world?
Colonic adenocarcinoma
What are the symptoms of colonic carcinoma?
- can have none
- anaemia
- rectal blood loss (high risk)
What is the aetiology of colonic carcinoma?
- Most arise in polyps within the surface of the lumen
- these polyps will grow with time and eventually progress into tumours
What is the aim of bowel cancer screening?
To detect polyps before they become cancerous
Why do polyps tend to bleed?
Due to irritation and trauma from bowel contents passing through
What are medical and familial factors linked to colonic carcinoma?
- genetics (p53 gene)
- ulcerative colitis
- intestinal polyps
What syndrome is characterised by development of polyps in the GI tract, and usually presents with dark-coloured spots on the lips?
Peutz-Jehgers syndrome
What part of the GI tract is at higher risk of colonic carcinoma, small or large intestine?
Large intestine
What two inherited conditions are characterised by many polyps/growths in the small and large intestine?
- Gardiners syndrome
- cowdens syndrome
Which inherited condition is particularly associated with mucosal polyposis?
Cowdens syndrome
How are Colton cancers staged?
According to the level of invasion of the bowel wall
What is stage 0 colon cancer?
There is no evidence of cancer in the colon or rectum
What is stage 1 colon cancer?
The tumour has grown into the submucosa
What is stage 2 colon cancer?
Tumour has grown into the Muscularis propria, a deeper thicker layer of muscle that contracts to force content along the intestines
What is stage 3 colon cancer?
Tumour has grown through Muscularis propria and into connective tissue or into tissues surrounding the colon or rectum.
What is stage 4 colon cancer?
The tumour has grown through the bowl wall and to the regional lymph nodes and beyond to other surrounding organs and structures
What are the 4 potential treatments for colonic carcinoma?
- Surgery (primary treatment)
- Hepatic metastases
- Radiotherapy
- Chemotherapy
What is involved in the surgery for colonic carcinoma?
- Resection of the bowl tissue
- Bowl brought out through patients abdomen as a stoma
- Lumen empties into a bag which is placed over the stoma
What is a stoma?
Mucosal surface of the bowl turned upwards so that the lumen empties into a bag
What is the screening test used for colonic carcinoma in the UK?
FiT test (Faecal immunochemical test)
If an FiT test (Faecal immunochemical test) comes back negative, when is it next necessary to repeat the test?
2 years later
If an FiT test (Faecal immunochemical test) is positive, what procedure usually follows?
Endoscopy
Define, “ the loss of the surface of teeth due to acids you eat or drink, or acids coming up from your stomach”?
Erosion
Define, “ the wearing of incisal or occlusal surfaces of teeth as a result of functional tooth-to-tooth contact”?
Attrition
Define, “ the wearing away of tooth surface caused by friction or mechanical process”
Abrasion
What is the most common site to be effected by erosion?
palatal surfaces of upper anterior teeth
What are the three main causes of dental erosion?
- Acidic foods/diet
- GORD
- Excessive vomiting (bulimia, morning sickness)
Why do oral manifestations of coeliac disease occur?
Due to the effects of nutritional deficiency from malabsorption
What are oral signs of coeliac disease?
- apthous ulcers
- glossitis
- angular cheilitis
What size is a minor apthous ulcer?
<1cm
What size is a major apthous ulcer?
> 1cm
What is the most common orofacial sign of Crohn’s disease?
Facial/labial swelling
In Crohn’s disease, what orofacial sign usually results from granulomatis inflammation and oedema of tissues?
Cobblestone mucosa
What is meant by “staghorning”?
Submandibular ducts become raised and prominent in appearance, this is secondary to swelling
Define, a chronic inflammatory disorder of the orofacial region characterised by non-caseating granuloma on histopathology?
Oro-facial Granulomatosis (OFG)
How does OFG commonly present in individuals?
As lip/oral/facial swelling and gingival involvement
Histologically and clincially, what disease is very similar to OFG?
Crohn’s disease
What is the most notable difference between OFG and Crohn’s disease?
OFG tends to have absence of GI symptoms
How are OFG and crohn’s similar histologically?
They both have presence of non-keratinising granuloma within tissues
What is thought to be the most likely cause of OFG, although aetiology still remains largely unknown?
Hypersensitivity to food preservatives/ dental materials
What are the three potential oral manifestations of ulcerative colitis?
- apthous ulcers
- lesions related to anaemia
- pyostomatitis vegetans
What is pyostomatitis vegetans?
A rare disorder characterised by erythema and oedema of the mucosa and numerous small superficial yellow pustules
