Gastrointestinal (GI) Flashcards
In the ABC criteria for Irritable Bowel Syndrome, what does A, B and C stand for?
Abdominal pain or discomfort
Bloating
Change in bowel habit
The most commonly used anti-diarrhoeal medication and its mechanism of action…
Loperamide/Imodium
Opioid that does not enter the CNS, works to slow down the GI tract/gut motility for colon to absorb more water and form stool.
In what (4) circumstances is Loperamide contraindicated?
Acute severe ulcerative colitis
Fever
Blood in stools
Suspecting C.Diff infection
The two antibiotics used for treating Clostridium difficile (C.Diff)…
Metronidazole (oral or IV)
Oral Vancomycin
Bulk forming laxative used for treating constipation…
Fybogel/Ispaghula husk
Class of laxative AVOIDED in IBS-C. Why?
Osmotic Laxatives, e.g. Lactulose.
Side effects: Flatulence + abdominal bloating which are already symptoms of IBS.
Laxative AVOIDED in opioid-induced constipation. Why?
Bulk forming laxative, Fybogel/Ispaghula husk. Prevents peristalsis of the increased bulk, which worsens abdominal pain and can contribute to bowel obstruction
Inflammatory Bowel Disease - Name the two conditions
Ulcerative Colitis
Crohn’s Disease
The name of the stool sample test to distinguish between IBD and IBS/other causes? What is it/why do we use it?
Faecal Calprotectin.
Elevated faecal calprotectin indicates the migration of neutrophils to the intestinal mucosa, which occurs during intestinal inflammation.
What (9) features (red flags) would make you cautious to diagnose IBS?
Anaemia, Fever, Persistent diarrhoea or constipation, Rectal bleeding, symptoms at night, Family history of colon cancer, unexplained weight loss, onset of symptoms over the age of 50.
In Ulcerative Colitis, how is the inflammation characterised?
Mucosa and sub-mucosal inflammation only
In Crohn’s Disease, how is the inflammation characterised?
Transmural inflammation - affecting the mucosa, sub-mucosa and muscularis externa
First line treatment for inducing remission in mild to moderate ulcerative colitis… What is used if it is contraindicated/not tolerated?
Aminosalcylate - Mesalazine. Oral or topical depending on region of the colon that is affected.
Not tolerated - oral or topical steroid (budesonide)
First line treatment for severe/acute ulcerative colitis… What is used if it is contraindicated/not tolerated?
IV steroids (hydrocortisone).
Not tolerated - IV cyclosporine (immunosuppressant)
First line treatment to induce remission in Crohn’s Disease… What is used if this is contraindicated/not tolerated?
Steroids
Not tolerated - aminosalcylate
In Crohn’s Disease, what medications are used if the patient experiences >2 exacerbations per year or if unable to wean steroids?
Methotrexate OR Azathioprine (Immunosuppressants)
A diagnosis of IBS should be considered only if the person has abdominal pain or discomfort that is either relieved by defaecation or associated with altered bowel frequency or stool form. This should be accompanied by at least two of the following four symptoms:
(1) Altered stool passage (straining, urgency, incomplete evacuation)
(2) Abdominal bloating (more common in women), distension, tension or hardness
(3) Symptoms made worse by eating
(4) Passage of mucus.
Name the 4 sections of the stomach
Fundus, Cardia, Body, Pylorus
Name the 4 layers of the stomach
Mucosa, Sub-mucosa, Muscularis, Connective tissue layer
What layer of the stomach are the gastric pits found?
Mucosal Layer
Name the cell types within the gastric pits and their functions
Goblet cells - Secrete mucus to protect stomach lining, at neck of gastric pit
Parietal cells: Secrete Gastric Acid (HCL) in response to stimulation by G cells.
G cells: Secrete Gastrin - acid stimulator, trigger pepsinogen and HCL release
D cells: Secrete somatostatin, hormone to slow down/inhibit acid secretion
Chief cells: Secrete Pepsinogen (Activated by HCL in stomach lumen into Pepsin)
Identify the three main hormones that are activated to aid in digestion
Gastrin - Produced by G cells, stimulates the release of intrinsic factor and gastric acid from parietal cells, promotes gastric motility.
Pepsin - Produced by chief cells; activated by H+ to convert pepsinogen to pepsin and starts the digestive process.
Secretin - Produced by s cells of the duodenum. Stimulates the secretion of HCO- from pancreas in response to heightened acid production.
Risk factors for developing GORD
Asthma, Obesity, Fatty meals (delayed gastric empyting), Smoking, Hiatus hernia, Pregnancy, Alcohol, Caffeine, Lying flat after eating
Complications/Consequences of GORD
Ulceration
Oesophagitis
Barrett’s oesophagus
Oesophageal cancer
Define Barrett’s Oesophagus
A well recognized as a complication of GORD/Oesophagitis
Replacement of the normal squamous epithelium lining the lower oesophagus with columnar epithelium - metaplasia
This may progress to malignancy
Risk factors for developing Barrett’s Oesophagus
Family history Being male Being white Age ChronicGORD Current or pastsmoking Obesity
(4) Risk factors for developing a hiatus hernia
Age 50+
Female
Obesity
Pregnancy
Define: Oesophageal varices
Extremely dilated, enlarged and/or swollen veins in the lower third of the oesophagus, commonly caused by portal hypertension, caused by liver cirrhosis.
Define: Mallory-Weiss Tear/Syndrome
Upper gastrointestinal bleeding from a longitudinal mucosal tear in the upper gastrointestinal tract.
This is usually at the gastro-oesophageal junction or gastric cardia.
Usually as a result of forceful vomiting/retching.
Risk factors for developing Gastritis
Infection with H.Pyloria, NSAID/Aspirin use
MOA of Antacids
Neutralise the stomach acid and increase the pH of the stomach.
Antacids are temporary. The stomach empties out its contents (including the antacid), makes more acid, re-creating the problem/symptoms.
MOA of H2 Antagonists, give drug name examples
Normally , histamine combines with H2 receptor on parietal cells, activates it and makes the stomach produce more acid.
H2 Antagonists stop histamine from binding to receptor to activate acid secretion.
Drug name = Ranitidine
MOA of PPIs, give drug name examples
PPIs work by blocking the H+/K+ ATPase proton pump - the final step before stomach acid production.
They are effective, an almost complete blockade, and irreversibly bind to the pump
Define Divertculae, Diverticulosis, Diverticular disease, and Divertculitis
Diverticula are sac-like protrusions of mucosa through the muscular wall.
Diverticulosis is defined as the presence of diverticula which are asymptomatic.
Diverticular disease is defined as diverticula associated with symptoms.
Diverticulitis is defined as evidence of diverticular inflammation (fever, tachycardia) with or without localised symptoms and signs.
Where in the GIT are diverrticula commonly seen?
Sigmoid and descending colon.
What (6) factors increase the risk of developing diverticulitis?
Age, smoking, obesity, high fat-low fibre diet, constipation and lack of exercise.
Name the two types of colonic polyps
Hyperplastic Polyps: Common, small and considered extremely low risk for turning cancerous.
Adenomas: About 70 percent of all polyps are adenomatous. Only a small percentage actually become cancerous, but nearly all malignant polyps began as adenomatous.
Identify the (4) risk factors for colonic polyps
Elderly, Family History, Previous history of polyps, Male gender
Symptoms/red flags that may be suggestive of colorectal cancer…
Anaemia Unexplained appetite loss Unexplained weight loss Blood in stools/rectal bleeding Change in bowel habits Abdominal/rectal mass
(6) Risk factors for colorectal cancer
Aged over 50 Colorectal polyps Family history of colon cancer Personal history of cancer Inflammatory bowel disease Cigarette smoking
Signs and symptoms of appendicitis
Abdominal pain - typically starts in the umbilical region and migrates to the RIF Anorexia (loss of appetite) Nausea and vomiting Fever Signs of sepsis
On examination of a patient with appendicitis, what signs are you most likely to see?
RIF tenderness (commonly at McBurney’s point)
Rovsing’s sign - pain in RLQ on palpation of the LLQ
Obturator sign - pain on internal rotation and flexion of right thigh
Signs of peritonitis
