Small intestine and colon and stomach Flashcards
How long does food typically stay in the stomach?
3-5 hours
What is secreted into the stomach to absorb vitamin b12
Intrinsic factor
What is the purpose of the cardia, fundus and pylorus of the stomach?
Cardia: area of lower esophageal sphincter that secretes mucus
Fundus: upper pouchish area that secretes mucus and HCl and pepsin
Pylorus: Lower sphincter that pushes food into intestine
What’s the antrum?
The stomach part of the pylorus. The pylorus is just the name of the opening of stomach to small intestine
What allows the stomach to expand in volume?
Rugae
How much volume can a stomach hold?
1.5 gallons
How deep are the gastric glands in the antrum? the fundus? the cardia?
Most shallow in antrum and deepest in fundus
Cardia is intermediate
What are the gastric glands and what do they secrete?
Surface mucus cells: mucus and bicarb
Mucus neck cells: mucus
Parietal cells: Requires gastrin to be activated
Secretes HCl and intrinsic factor
Chief cells: Pepsinogen
Endocrine cells: G cells (increase gastrin) and D cells (decreases gastrin)
What is the pathophysiology for gastric ulcers?
Mucosal defects in stomach and early small intestine - recurrent ulcers
Symptoms of gastric ulcer?
Dull, gnawing pain
Blood in GI - Melena, Hematemesis, Guaiac (+) stools
Anemia
Predilection of gastric ulcers?
Slight predilection to men
15-65. P much all ages
Causes of gastric ulcers?
H pylori
Most people have it but only 10-15% get ulcers
NSAIDs/Aspirin
Damage surface cells - less mucus and bicarb produced
Tests for gastric ulcers?
H pylori serum antibody test
Urea breath test
Stool antigen test
Endoscopy most definitive
Treatment for gastric ulcers?
Triple therapy: PPI + clarithromycin + metronidazole
Stop NSAIDs/aspirin: if can’t add PPI or misoprostol
If severe bleeding: endoscopic hemostasis
Complications of gastric ulcers?
Bleeds, Perforations, edema that can lead to obstruction
Describe stress gastritis
Superficial nonulcerating lesions in stomach
What can cause stress gastritis?
Trauma, shock, sepsis, respiratory failure
Does stress gastritis typically cause bloody stools?
No, it’s just a focal lesion, but if it erodes deeper to submucosa, it could be a frank bleed
Pathophysiology of stress gastritis?
Stress = decreased gastric defense = decreased blood flow to area = decreased HCl and bicarb
OR could be an too much gastric acid in body
How do you treat stress gastritis?
Treat underlying cause and keep pH over 5
If becomes frank bleed of more than 6 units or if it’s recurrent, do surgery
What’s the 2nd leading cause of death in the US?
Gastric cancer
Predilection for gastric cancer?
Asians and S. Americans over 50
Risks of gastric cancer?
High nitrate foods (meats and fish)
Smoking and alcohol
Polyps, atrophy or gastritis of stomach
Symptoms of gastric cancer?
Typical cancer symptoms
Heart burn and anemia
Stomach pain and swelling
Full after small meals
Workup for gastric cancer?
Endoscopic ultrasound
CT/MRI/PET scan
Prognosis for gastric cancer
20% survival rate (obviously better if found early)
What are the parts of the small intestine called starting at the stomach?
DJ Ill!
Duodenum
Jejunum
Ileum
What’s the function of the small intestine
Absorb nutrients from chyme from stomach
What enzyme digests carbs?
Amylase: mouth and pancreas
Other enzymes from small intestine
What enzyme digests proteins?
Pepsin (chief cells) and trypsin (as trypsinogen from pancreas)
What enzyme digests fats?
Bile from liver and lipase
What happens to carbs before they’re digested?
Broken into mostly glucose, but also fructose and galactose
Where are proteins mostly absorbed?
Jejunum
Where are fats absorbed?
Small intestine in general
What else does the small intestine absorb?
Water, electrolytes, vitamins
What disease is a result of T cells reacting to proline and glutamine in food?
Celiac’s
Predilection for Celiac’s?
Adult white female with thyroid problems or DMI
More likely to get it if exposed at early age
Symptoms of Celiac’s?
Asymptomatic
Greasy, smelly pale poops
Pathophysiology of Celiac’s?
Person eats gluten, broken down into proline and glutamate. T cells activated, cytokines released and mucosal membranes are damaged
What lab tests would you do for Celiac’s?
anti-tTGA (tissue transglutiminase) IgA test
HLA-DR2 gene test
Most definitive: Biopsy and try stopping gluten for a while
How do you treat Celiac’s? How to do you ensure patient compliance?
Stop eating gluten and make sure not malnourished
Do anti-tTGA test to ensure compliance
How long does it take for mucous membranes to recover from Celiac’s?
6 - 24 months
What is gluten?
Proline and glutamine
What were the tests for Celiac’s again?
anti tTGA
HLA DR2
Biopsy/try to stop eating gluten (Definitive)
What is another name for gastrinoma?
Zollinger Ellison syndrome
Epidemiology of Gastrinoma?
Middle aged white males with MEN1 gene
Symptoms of gastrinoma
Heart burn, abdominal pain and diarrhea
Pathophysiology of gastrinoma?
Tumor occurs in gastrinoma triangle (Gall bladder, pancreas and s. intestine) that secretes gastrin. Gastrin activates parietal cells to release HCl and intrinsic factor. Too much HCl = more ulcers and small intestine
How would you work up a gastrinoma?
Endoscopy, MRI, CT, ultrasound to view it
Determine [HCl] in body
less than 100pg/mL normal
Greater than 1000pg/mL = danger
Treatment for gastrinoma?
Remove gastrinoma
PPI, Somatostatin analog of D cells (decreases gastrin)
Prognosis for gastrinoma?
No metastases: 90% 5 year survival
Metastases to liver: 20% 5 year survival
What do gut bacteria synthesize in the large intestine?
Vitamins B and K
What is the role of the large intestine?
Water and electrolyte absorption (Na, K, CL)
List the parts of the small intestine as it leaves the small intestine
Cecum, Ascending, Transverse, Descending, Sigmoid
What’s irritable bowel syndrome and how long does it typically last?
Tummy pain linked with bowel function. Usually lasts about 6 months
What relieves pain associated with IBS?
Pooping
Epidemiology of IBS?
Ladies 20-40 years old. About 15% population affected
What tests can you run for IBS?
No direct tests. Just rule out other diseases
Pathogenesis of IBS?
Increased colon motility after meals
Increased pain sensitivity upon gut stimulation
Stomach flu
Risk factors for IBS?
Psych issues, abuse
Treatment of IBS?
Fix poops with antidiarrheals, laxatives or suppositories
Antidepressants and psychotherapy
Change diet and add fiber
Prognosis of IBS?
Chronic and relapsing but greater than 60% respond to Tx
What’re the types of IBD?
Ulcerative colitis
Crohn’s
Similarities between ulcerative colitis and Crohn’s?
Idiopathic
Increase number of poops
Decrease poop consistency
results in weight loss
What are some very general differences between ulcerative colitis and Crohn’s?
Crohn’s: Rt lower abdominal pain, Discontinuous, May include ileum, Pain
Ulcerative colitis: Lt lower abdominal pain, continuous, never includes ileum, blood
How does Crohn’s affect the structure of the colon?
Very inflamed and cobblestoney. Can affect anything from esophagus to colon
How does Ulcerative colitis affect the structure of the colon?
Many ulcers. Results in pseudopolyps and can also result in bleeding. Inflam starts at anus and goes up. Also have crypt distortions (cell type)
What are other systemic manifestations that can occur with IBD?
1/3 of people with IBD also have systemic manifestations
Eyes: Episcleritis and uveitis
Skin: Erythema and gangrene
Joints: Peripheral arthritis and ankylosing spondylitis
How do you diagnose IBD?
Imaging with sigmoid, capsule, colon, or double balloon endoscopy (Double balloon is colon to small intestine)
Can also do CT with contrast* and MRI
How do you treat IBD?
Antiinflammatories: Corticosteroids and tesalazine
If Crohn’s, may also need surgery
Colectomy. If Ulcerative colitis may need ileal pouch-anal anastomoses
Resection of inflamed tissue (usually ileum) for Crohn’s
What’s a diverticula?
Outpouching of large intestine wall
Who is more prone to diverticula?
Less prone?
Older males. Vegetarians are less prone
What is the cause of diverticulitis?
When diverticula gets filled with poop, causing inflammation and microperforation
Symptoms of diverticulitis?
Nausea, vomitting, diarrhea and constipation as well as abdomen pain
How would you diagnose diverticulitis
Health Hx and Imaging via CT and ultrasound
How do you treat diverticulitis with no perforation?
Antibiotics and liquid diet
How do you treat diverticulitis with perforation?
Rest colon, antibiotics and hospitalization for surgery
Prevalence of colorectal cancer?
2nd most common cancer. Seen in men over 50
Risk factors of colorectal cancer?
FHx, High fat, low fiber diet, sedentary lifestyle
Symptoms of colorectal cancer?
Abdominal pain, fecal impacting/obstruction, bleeding, constipation and tiny poops
At what age should you get screened for colorectal cancer? How often should you get one?
50 years old
Sigmoidoscopy: 3-5 years
Colonoscopy: 10 years
Compare and contrast sigmoidoscopy and colonoscopy.
Sigmoidoscopy may miss 50% of lesions. Best done with fecal occult blood test. Patient NOT sedated
Colonoscopy much better. Sees entire colon and can biopsy and remove polyps. Patient sedated
How would you treat colorectal cancer?
Colon resection, prophylactically remove polyps
What’s the hallmark sign of Gardner’s syndrome?
Many many many (a garden of) polyps in large intestine
What is Gardner’s syndrome?
Subtype of FAP (familial adenomatous polyposis)
What hereditary pattern is Gardner’s?
Autosomal dominant (APC) or autosomal recessive (MYH)
When should a child be screened for Gardner’s?
When should they get genetic testing?
Screened at 12 yo
Genetic testing at 10yo
How would you treat Gardner’s?
Resection
What may we notice in a patient with Gardner’s? What could we do if we notice this sign?
CHRPEs (AKA POFLs or Bear tracks)
Refer to PCP
