Lower GI tract Flashcards by Niamh Sands

What makes up the lower GI tract

Jejunum
Ileum
(appendix)
Caecum
Colon (ascending, transverse, descending, sigmoid)
Rectum
Anus

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What are the diseases associated with the lower GI tract

Coeliac disease

Inflammatory bowel disease

Bowel cancer

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What percentage of the popln have coeliac disease

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What is coeliac disease

An autoimmune disease
Triggered by eating gluten (barley, rye, wheat)

Peptide molecules

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What is the pathophysiology of coeliac disease

Loss of immune tolerance to gluten

Autoantibodies created (anti-tTG*)

Target the epithelial cells of small intestine

Inflammation of intestinal wall - reduced area for absorption

Results in gut symptoms and malabsorption

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What reduces the surface area with coeliac disease

Inflamation (atropphy) of the villi

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Absorption of what substances are impacted by coeliac disease

Iron*

Folic acid

Vitamin B12

Calcium

Vitamin D

Fat

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What are the symptoms of coeliac disease

Abdominal pain

Bloating

Diarrhoea

Nausea and vomiting

Weight loss

Fatigue

Recurrent oral ulcers

Children – failure to thrive

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How is coeliac disease tested for

Patient must continue eating gluten when being investigated for coeliac

Bloods: - FBC, haematinics
- anti-tTG antibody (tissue transglutaminase) – first line*
- EMA (endomysial antibody) – second line

Endoscopy + duodenal biopsy (gold standard)
Classic findings: villous atropy, crypt hyperp

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How is coeliac disease managed

Gluten-free diet - dietician input (barley, rye, wheat)

Improves symptoms
Reverses histological changes
Reduces lymphoma risk

Correct deficiencies (iron, folate, B12

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What are some possible complications/effects of having coeliac disease

Nutritional deficiencies

Anaemia

Osteoporosis

Dermatitis herpetiformis

Lymphoma of small intestine*

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What causes dermatitis herpetiformis

As a result of autoantibodies (IgA) being deposited in skin

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What are the dental implications of coeliac disease

Children
Tooth development (enamel hypoplasia, delayed eruption)

Haematinic malabsorption
-Recurrent oral ulceration – need to exclude coeliac disease
-Glossitis (atrophic if iron)
-Oral dysaesthesia
-Angular cheilitis
-Candidal infections

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What is inflammatory bowel disease

Recurrent episodes of inflammation in the gastrointestinal tract

Exacerbation and remission

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What are the two main types of inflammatory bowel disease

Crohn’s disease

Ulcerative colitis

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What causes inflammatory bowel disease

Immunologically driven, cause = unknown

Genetic susceptibility

Gut microbiome

Psychosocial (stress, trauma)

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What are the shared symptoms of crohn’s disease and ulceerative colitis

Weight loss

Fatigue

Abdominal pain

(Bloody) diarrhoea

Rectal bleeding

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What does crohn’s disease do to the lower GI tract

Inflammation of GI tract wall
-Can involve any part of GI tract (mouth to anus)
-Most commonly ileo-caecal and perianal regions

Transmural inflammation
-Full thickness of GI wall – all layers

“Skip lesions”
-Alternating regions of involved and non-involved tissue

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What is the pathophysiology of crohn’s disease

Trigger

Inflammatory infiltrate (CD4, CD8, B cells, monocytes)

Ulceration of mucosa

Invasion of deeper mucosal layers

Formation of granulomas

Formation of crypt abscesses

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What is a granuloma

A tight cluster of immune cells, in an attempt to isolate a foreign pathogen or irritant

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What are the tests for crohn’s disease

Bloods:
-FBC, haematinics
-CRP (inflammatory marker)
-anti-tTG (to exclude coeliac disease)

Faecal calprotectin:
stool sample analysed, calprotectin produced by gut when inflammation is present

Colonoscopy + biopsy- Classic biopsy findings:
Transmural inflammation
Granulomas (non-caseating)
Crypt abscesses

What surgical management of crohn’s disease is there

Up to 80% patients

Resection of persistently inflamed bowel

Usually results in stoma (ileoectomy/colectomy)

What madication is given for crohns disease

Immunosuppressants:
Azathioprine
Mercaptopurine
Methotrexate
Biologics (infliximab)

What induces remission of crohns disease

Corticosteroids (e.g. oral prednisolone, IV hydrocortisone)

What are the possible complications of crohn's disease

Fistula Severe abdominal infections Anaemia (malabsorption of iron/folate/B12) Orofacial involvement* (up to 60%)

What are the dental implications/symptomsof crohns disease

Buccal oedema Cobblestoning (buccal surface bumpy) Linear, sulcal ulceration Mucosal tags Lip fissuring

What is orofacial granulomatosis (OFG)

Heterogenous group of conditions resulting in orofacial swelling Granulomatous inflammation

What would a very swollen face and lips possibly indicate

Crohn's disease (OFG)

What is the difference in the inflammation of ulcerative colitis and crohn's disease

Only superficial mucosa affected Unlike Crohn’s

What is ulcerative colitis

Inflammation of GI tract wall Limited to colon and rectum, never into small intestine Only superficial mucosa affected Continuous inflammation Starts at rectum and moves proximally (“up the GI tract”)

What is the pathophysiology of ulcerative colitis

Trigger (genetic/environmental/previous GI infection/smoking is protective) Leaky gut epithelial barrier Antigens activate mucosal immune cells Dysregulated immune response Ulceration of gut mucosa Formation of crypt abscesses

How is ulcerative colitis tested for

Bloods: FBC, haematinics CRP (inflammatory marker) anti-tTG (to exclude coeliac disease) Faecal calprotectin: stool sample analysed, calprotectin produced by gut when inflammation is present Colonoscopy + biopsy-Classic biopsy findings: No inflammation beyond submucosa Widespread ulceration Crypt abscesses No granulomas

What surgery is suggested for ulcerative colitis

Panproctocolectomy is curative (removal of entire large bowel and rectum)

What management options for ulcerative colitis are there

Inducing remission Mild/moderate: rectal or oral mesalazine (5-ASA) Severe: IV hydrocortisone Maintenance -Rectal mesalazine -Azathioprine -Mercaptopurine

What are some complications of ulcerative colitis

Toxic megacolon – sepsis/death Bleeding (haemorrhage) Bowel cancer* Primary sclerosing cholangitis Bile duct scarring Red eye conditions (episcleritis, anterior uveitis)

What are the dental implications of IBD

Orofacial features of CD -Buccal oedema -Linear, sulcal ulcers -Mucosal tags -Buccal cobblestoning -Lip fissure Malabsorption -Haematinic deficiency – recurrent oral ulceration Stomatitis gangrenosum (1%) -Ulcer with necrotic borders Drug-related -Corticosteroids – candidosis -Methotrexate – oral ulcer

What are the modifiable risk factors of bowel cancer

- Dietary red meat - Low dietary fibre - Obesity - Smoking - Alcohol - Not engaging with screening

What are the Non-modifiable risk factors of bowel cancer

- Age >50 - Family history - IBD (UC) - Intestinal polyps

What does bowel cancer affect

Colon or rectum small intestine less common

What type of tumour is bowel cancer

Adenocarcinoma

How is bowel cancer detected

Colonoscopy + biopsy (gold standard) Staging CT scan (chest, abdomen and pelvis – to look for metastasis)

What are the symptoms/signs of bowel cancer

Change in bowel habits (constipation, diarrhoea, tenesmus) Bleeding (in stool or on wiping) Unexplained weight loss Iron deficiency anaemia Abdominal mass Abdominal pain/discomfort

How is the treatment for any cancer patient decided

By multidisciplinary team Surgeons / radiologists / pathologists / oncologists / nurse specialists And by patients wishes

What are the management options for bowel cancer

Surgery Chemotherapy Radiotherapy Palliative care

What does the MDT's decision depend on when deciding how to treat cancer

Stage of cancer Grade of cancer Medical history Performance status (fitness) Patient and family wishes

What is required after surgical management of bowel cancer

Stoma

How is bowel cancer screening carried out in scotland

Every 2 years to men and women aged 50-74 (Scotland) FIT (faecal immunohistochemical test) Essentially identifies and quantifies haemoglobin in stool

What is done if a screening patients sample is abnormal

Colonoscopy

What are the dental implications of bowel cancer

Anaemia as a presenting symptom -We can pick this up and signpost Effects of cancer treatment -Chemo- / radiotherapy

What guidelines can a dentist consult when treating cancer patients

RCS - the oral management of oncology patients requiring radiotherapy,chemotherapyand/or bone marrow transplantation