Week 11 - Terms; Gastrointestinal Health Flashcards
List the components of the large bowel
a. Cecum (+ appendix)
b. Ascending colon
c. Transverse colon
d. Descending colon
e. Sigmoid colon
f. Rectum
List the components of the stomach
a. Cardia, Antrum, Fundus, Pylorus
b. Pyloric valve
List the components of the small bowel
a. Duodenum, Jejunum, Ileum
b. Ileocecal valve
Describe the general structure of the GI tract
- Lumen: hollow space in the GI tract
- Mucosa: inner lining
o Varies by site depending on function - Muscularis: muscle layer
o Contents move through GI tract through coordinated wave-like contractions (peristalsis)
Describe the peritoneal cavity
-Continuous membrane that forms the lining of the abdominal cavity
-Diseases of the GI tract can involve the peritoneal cavity
-Can fill with fluid (ascites), or become inflamed (peritonitis)
What are the functions of the GI tract?
- Digestion
2.Absorption – taking up nutrients and/or water for use
a. Nutrient absorption occurs in small bowel
b. Water and electrolyte absorption occur in large bowel - excretion
Define hematemesis
vomiting of blood; “Coffee grounds emesis” – dark and granular vomitus due to effects of stomach acid on hemoglobin
Define hematochezia
Indicates “fresh” bleed, commonly from lower GI tract
Hematochezia is a common finding in what?
ulcerative colitis
Define melena
Dark, black, tarry stool; Stool colour due to digestion of blood, most commonly from upper GI tract
Define occult bleeding
Blood that is not visible in stool; May be picked up on screening stool tests (fecal blood tests/FIT tests)
FIT test is a common screening tool for what?
colorectal cancer; to detect occult blood. Positive results - patients may have iron deficient anemia (blood work) and/or be sent for colonoscopy
Infections of the GI tract can be caused by what and can occur where?
- Can be caused by viruses, bacteria and/or parasites, and can occur in any segment of the GI tract
Define appendicitis
Inflammation of the appendix
What is the pathogenesis of appendicitis?
Often associated with fecalith obstruction (obstruction of blood flow (ischemia)
leading to ulceration and secondary infection)
What are the risk factors for appendicitis?
o Extremes of age
o Family history
o Male sex (M>F)
What are the signs and symptoms of appendicitis?
o Abdominal pain (RLQ/McBurney’s point)
Rebound tenderness
o Nausea/vomiting
o Fever
What are the complications of appendicitis?
o Can lead to appendiceal rupture (perforation) leading to peri-appendiceal abscess or inflammation of the peritoneal cavity (peritonitis)
What is the treatment for appendicitis?
surgery is most common in acute cases - appendectomy
Describe H. pylori (helicobacter pylori)
- Helicobacter pylori (H. pylori) is a Gram-negative bacterium, mostly commonly colonizes stomach
- Estimated prevalence 50% worldwide, higher in developing countries
What are the signs and symptoms of H. pylori?
o Often asymptomatic
o Common symptoms: abdominal pain (mid-upper), nausea, bloating
What are the complications of H. pylori infection?
o Peptic/duodenal ulcers in 10-15% of cases (disintegration of the epithelial lining) which can lead to bleeding and perforation
o Chronic inflammation leading to increased risk of lymphoma and cancer
How do you diagnose H. pylori infection?
- Diagnosis of H. pylori infection/peptic ulcer disease via endoscopy + biopsies, bloodwork, and/or urea breath test
What is the treatment for H. pylori infection?
Triple-therapy (antibiotics and protein-pump inhibitors)
What is the typical age for onset of inflammatory bowel disease?
15-35
What are the two types of IBD
crohn’s disease and ulcerative colitis
What are the common symptoms of IBD
o Diarrhea (+/- blood - only in UC) and urgency
o Abdominal pain
o Fever
o Weight loss/fatigue
o +/- extraintestinal problems (liver, joints, skin, eyes)
What are the sites of involvement in Crohn’s disease?
- Ileum and colon
- Can involve any part of GI tract
- Patchy involvement
What are the sites of involvement in ulcerative colitis?
- Starts at rectum and moves proximally
- Limited to colorectum
- Continuous involvement
Hematochezia is common in which IBD?
ulcerative colitis; uncommon in crohn’s disease
What is the degree of inflammation for Crohn’s disease?
Transmural - involving the entire bowel wall
What is the degree of inflammation for ulcerative colitis?
superficial
Which IBD leads to a greater risk of colorectal cancer
ulcerative colitis
How are IBDs treated and surveilled?
- Medications to reduce inflammation (anti-inflammatories, immune system modulators, biologics)
- Symptom relief for stools, nutritional support
- Surveillance endoscopy
- Surgery
o Crohn’s disease: removal of damaged sections, management of abscesses/fistulas
o Ulcerative colitis: removal of colon/rectum
Define diverticulum
outpouching of bowel wall
Define diverticular disease
presence of diverticula in the bowel
What is thought to be the cause of diverticula
increased luminal pressure (low fiber, high fat diets) and weak points in gut wall
Define diverticulitis
inflammation of diverticula
What are the symptoms of diverticulitis?
fever, worsening abdominal pain (LLQ)
What are the complications of diverticulitis
abscess formation, perforation, strictures, fistulas
What is the treatment for diverticulitis
antibiotics, surgery (depending on severity)
What are the four common causes of bowel obstruction
- Herniation: Pouch-like protrusion of peritoneum
- Adhesions: Fibrosis/scar tissue forming between loops of bowel
- Volvulus: Twisting of bowel on itself and mesentery
- Intussusception: Telescoping of bowel into adjacent segment
In children, where does bowel obstruction most commonly occur?
ileocecal valve
What are the common signs and symptoms of bowel obstruction?
o Abdominal distention
o Vomiting
o Constipation
Describe bowel obstruction
- Blockage that prevents the passage of food/liquids
- Can occur across all age groups, with a variety of causes
What is the third most commonly diagnosed cancer in Canada?
colorectal cancer
What is the most common type of colorectal cancer?
adenocarcinoma
Describe the pathogenesis of colorectal cancer
Mutations in the bowel mucosa may result in pre-cancerous (pre-malignant) legions called polyps
- Additional mutations may accumulate that result in local invasion or metastasis (cancer)
- Not all polyps result in cancer transformation
What are the signs and symptoms of colorectal cancer?
o Rectal/stool bleed
o Change in bowel habits
o Abdominal discomfort
o Weakness, fatigue, weight loss (unintentional)
What are the risk factors for colorectal cancer?
o Family history/known familial syndromes
o Age
o Inflammatory bowel disease
o Diet, obesity, smoking, (lack of) exercise
What are the risk factors for esophageal cancer?
- GERD
- Tobacco use
- Obesity
- Radiation
What is the most common type of esophageal cancer in Canada?
adenocarcinoma; worldwide it is squamous cell carcinoma
Where does esophageal cancer most commonly occur?
In the distal portion of the esophagus
Which GI cancer is more common (colorectal or esophageal)?
Colorectal cancer
What are the signs and symptoms of esophageal cancer?
(often at late stage)
- Pain or difficulty swallowing (dysphagia)
- Weight loss
- Chest pain
- Vomiting
Describe the pathogenesis of esophageal cancer
- Often arises in a background of chronic gastroesophageal reflux disease (GERD) acid reflux from stomach
- In approx. 10% of symptomatic GERD, the esophageal mucosa undergoes intestinal metaplasia (Barrett’s esophagus)
- Greater risk of developing dysplasia and malignancy
- Patients with Barrett’s esophagus may get PPIs and surveillance endoscopies
Someone presents with abdominal discomfort, fatigue, weight loss, and bloody stool, what is the likely diagnosis?
colorectal cancer; send for more testing though
What is the difference between diverticular disease and diverticulitis?
In diverticular disease, small bulges or pockets (diverticula) develop in the lining of the intestine. Diverticulitis is when these pockets become inflamed or infected.
Define dsyphagia
dysphagia - difficulty swallowing.
Define fistula
an abnormal duct or passage connecting an abscess, cavity or hollow organ to the body surface or to another hollow organ.
