Chapter 344 - Approach to the Patient with Gastrointestinal Disease Flashcards
How does the nervous system affect the gastrointestinal tract?
“Intrinsic gut wall nerves provide the basic controls for propulsion and fluid regulation. Extrinsic neural input provides volitional or involutary control to degrees that are specific for each gut region.”
Name the two main functions of the gastrointestinal (GI) tract.
“The GI tract serves two main functions - assimilating nutrientes and eliminating waste.”
What are the differences in functions of proximal versus distal stomach?
“The proximal stomach serves a storage function by relaxing to accomodate the meal. The distal stomach exhibits phasic contractions that propel solid food residue agasint the pylorus, where it is repeteadly propelled proximally for further mixing before it is emptied into the duodenum.”
What kind of nutrientes are absorved in the proximal intestine in comparisn to its distal portion?
“The proximal intestine is optimized for rapid abosrption of nutrient breakdown products and most minerals, whereas the ileum is better suited for absorption of vitamin B12 and bile acids.”
The ileocecal sphincter prevents coloileal reflux and maintains small-intestinal sterility,
True or False?
True.
Name the normal transit times in different gastrointestinal compartments.
“Whereas transit times in the esophagus are on the order of seconds and times in the stomach and small intestine range from minutes to a few hours, propagation through the colon takes more than 1 day in most inidividuals.”
Name the differences regarding function between the proximal and distal colon.
“The proximal colon serves to mix and absorb fluid, while the distal colon exhibits peristaltic contractions and mass actions that function to expel the stool.”
Name the main protective mechanisms of the gastrointestinal tract.
“Mucosal immune mechanisms include chronic lymphocyte and plasma cell populations in the epithelial layer and lamina propria backed up by lymph node chains to prevent noxious agents from entering the circulation. Antimicrobial peptides secreted by Paneth cells in the intestine further contribute to the defense mechanisms against pathogens in the lumen. All substances absorbed into the bloodstream are filtered through the liver via the portal venous circulation. In the liver, many drugs and toxins are detoxified by a variety of mechanisms.”
Which gastrointestinal functions might be altered by stress?
“The brain-gut axis further alters functions in regions not under volitional regulation. As an example, stress has potent effects on gut motor, secretory, and sensory functions.”
What is the most common intestinal maldigestion syndrome?
Lactase deficiency.
All the diseases that impair digestion and absorption might result in anemia, dehydration, electrolyte disorders, or malnutrion.
True or False?
False.
These outcomes might occur in celiac disease, bacterial overgrowth, infectious enteritis, Crohn’s ileitis, and radiation damage, for example. On the other end, enzyme deficiencies, such as lactase, do not produce adverse outcomes.”
How does Zollinger-Ellison syndrome might produce impaired digestion and absorption?
“Gastric hypersecretory conditions such as Zollinger-Ellison syndrome damage the intestinal mucosa, impair pancreatic enzyme activation, and accelerate transit due to excess gastric acid.”
Name conditions associated with acid gastric hypersecretion.
Zollinger-Ellison syndrome, G cell hyperplasia, retained antrum syndrome, and some patients with duodenal ulcers.
Name intestinal and colonic hypersecretion conditions associated with diarrhea.
“Common intestinal and colonic hypersecretory conditions cause diarrhea and include acute bacterial or viral infection, chronic Giardia or cryptosporidia infections, small-intestinal bacterial overgrowth, bile salt diarrhea, microscopic colitis, diabetic diarrhea, and abuse of certain laxatives. Less common causes include large colonic villus adenomas and endocrine neoplasias with tumor overproduction of secretagogue transmitters like vasoactive intestinal popypeptide.”
What is the most common cause of small-intestine and colonic obstruction?
Adhesions and cancer, respectively.
How do you define gastroparesis?
“Gastroparesis is the symptomatic delay in gastric emptying of meals due to impaired gastric motility.”
Name causes for constipation.
“Slow-transit constipation is produced by diffusely impaired colonic propulsion. Constipation also is produced by outlet abnormalities such as rectal prolapse, intussusception, or dyssynergia - a failure of anal or puborectalis relaxation upon attempted defecation.”
“Causes of constipation include obstruction, motor disorders of the colon, medications, and endocrine diseases such as hypothyroidism and hyperparathyroidism.”
Hyperthyroidism might cause accelerated transit with hyperdefecation.
True or False?
True.
Eosinophils in the esophageal histology are pathognomonic of eosinophilic esophagitis.
True or False?
False.
They might occur in other conditions such as gastroesophageal reflux disease.
Which microscopic colitides do you know and how do they differ from other inflammatory bowel diseases?
“The microscopic colitides, lymphocytic and collagenous colitis, exhibit colonic subepithelial infiltrates without visible mucosal damage.”
Which mechanisms might explain impaired gut blood flow?
“More commonly encoutered are intestinal and colonic ischemia that are consequences of arterial embolus, arterial thrombosis, venous thrombosis, or hypoperfusion from dehydration, sepsis, hemorrhage, or reduced cardiac output.”
Chronic ischemia may result in intestinal stricture.
True or False?
True.
What are tha main risk factors for esophageal cancer?
Chronic acid reflux for adenocarcinoma and alcohol or tobacco history for squamous cell cancer.
How does one explain familial clustering in functional bowel patients?
“Familial clustering is even observed in the functional bowel disorders, although this may be secondary learned familial illness behavior rather than a true hereditary factor.”
What is the most common cause of abdominal pain?
Irritable bowel syndrome and functional dyspepsia.
How frequent is heartburn in the general population?
Reported intermittently by at least 40%.
Nausea and vomiting might be associated with functional causes.
True or False?
True.
These include chronic idiopathic nausea and functional vomiting, for example.
How do you describe constipation?
“Constipation is reported as infrequent defecation, straining with defecation, passage of hard stools, or a sense of incomplete fecal evacuation.”
Both hypothyroidism and hyperparathyroidism are associated with constipation.
True or False?
True.
Name the causes of upper and lower gastrointestinal bleeding.
Upper gastrointestinal hemorrhage: ulcer disease, gastroduodenitis, esophagitis aswell as portal hypertensive causes, malignancy, tears across the gastroesophageal junction (Mallory-Weiss syndrome), and vascular lesions.
Lower gastrointestinal hemorrhage: proctologic causes (hemorrhoids and anal fissures), diverticula, ischemic colitis, and arteriovenous malformations aswell as neoplasm, inflammatory bowerl disease, infectious colitis, drug-induced colitis, and other vascular lesions.
Which skin lesions are associated with celiac disease?
Dermatitis herpetiformis.
Name four gastrointestinal conditions associated with worsening of symptoms after a meal.
Mechanical obstruction, ischemia, inflammatory bowerl disease, and functional bowel disease.
How does diarrhea change in response to fasting in malabsortive and secretory etiologies?
“Diarrhea from malabsorption usually improves with fasting, whereas secretory diarrhea persists without oral intake.”
Meals elitic dirrhea in some cases of inflammatory bowel disease and irritable bowel syndrome but defecation relieves the discomfort.
True or False?
True.
Name a gastrointestinal disease more frequent in the following population: (i) Asia; (ii) Northen Europe; (iii) Jewish descents.
(i) Gastric cancer
(ii) Celiac disease
(iii) Inflammatory bowel disease
What organs might be affected in vitamin B12 defficiency?
Stomach [intrinsic factor (IF) production], small-intestine (ileus, where B12 is absorved) and pancreas (pH optimization for the ligation IF-B12).
Name three examples of diseases that can be screened on urine samples.
Carcinoid, porphyria, and heavy metal poisoning.
Which initial structural test should be advocated in patients with suspected ulcer disease, esophagitis, neoplasm, malabsorption, and Barrett’s metaplasia?
Upper endoscopy.
Which patients might benefit from sigmoidoscopy?
“Sigmoidoscopy examines the colon up to the splenic flexure and is currently used to exclude distal colonic inflammation or obstruction in young patients not at significant risk for colon cancer.”
Which techniques might be used to assess the small-intestine mucosa?
Push enteroscopy, double-balloon enteroscopy and capsule endoscopy.
Name the uses for gastrointestinal endoscopic ultrasound.
“Endoscopic ultrasound is useful for evaluating extent of disease in GI malignancy as well as exclusion of choledocholithiasis, evaluation of pancreatitis, drainge of pancreatic pseudocysts, and assessment of anal continuity.”
What is the first initial test indicated in dysphagia?
Barium swallow test.
Virtual colonography with CT scanning or MRI are validated for neoplastic screening.
True or False?
False.
What are the main uses for gastrointestinal scintigraphy?
“Scintigraphy both evaluates structural abnormalities and quantifies luminal transit. Radionuclide bleeding scans localize bleeding sites (…) Radiolabeled leukocyte scans can serach for intraabdominal abcesses not visualized on CT. Biliary scintigraphy is complementary to ultrasound in the assessment of cholecystitis. Scintygraphy to quantify esophageal and gastric emptying is well established, whereas techniques to measure small-intestinal or colonic transit are less widely used.”
When does deep rectal biopsies assist in the diagnosis?
Hirschprung’s disease or amyloid.
Stomach, small-intestine and colon transit and motor function can be studied with a wiereless motility capsule.
True or False?
True.
How might one study unexplainted biliary pain?
This condition might be due to sphincter of Oddi dysfunction and it can be studied using biliary manometry.
Name two tests used to screen for small-intestinal bacterial overgrowth.
Culture of the aspirate following upper endoscopy and hydrogen measurement after challenge with oral mono- or oligossacharide challenge.
What is low-FODMAP diet for irritable bowel syndrome?
FODMP = Fermentable oligo-di-monosaccharides and polyols.
Adsorbents and antiflatulent drugs reduce gaseous symptoms.
True or False?
True.
Name the nutritional manipulation used for obstipation.
“Fiber supplements, stool softeners, enemas and laxatives are used for constipation.”
Which types of over-the-counter laxatives drugs are there?
“Laxatives are categorized as stimulants, osmotic agents (including isotonic preparations containing polyethylene glycol), and poorly absorbed sugars.”
Name the antidiarrheal agents.
Over-the-counter agents include bismuth subsalicylate, kaolin-pectin combinations, and loperamide.
Prescription drugs include opiate drugs, anticholinergic antispasmodics, tricyclics, bile acid binders, and serotonin antagonists.”
Name one non-neoplastic condition associated with severe pain which might have to be manageable with narcotics.
Chronic pancreatitis.
Name the therapy for abdominal pain associated with functional gastrointestinal disease
Antispasmodic and antidepressants.
Name the gastrointestinal conditions which might benefit from antibiotherapy.
“Antibiotics treat ulcer disease secondary to Helicobacter pylori, infectious diarrhea, diverticulitis, intestinal bacterial overgrowth, and Crohn’s disease. Some cases of irritable bowel syndrome (especially those with diarrhea) respnd to nonabsorbable antibiotic therapy.”
Which alternative therapies might be used for nausea?
“Ginger, acupressure, and acustimulation have been advocated for nausea, whereas pyridoxine has been investigated for nausea of first-trimester pregnancy.”
Which nonsurgical therapies might be used in acute colonic pseudoobstruction?
“Enemas relieve fecal impaction or assist in gas evacuation in acute colonic pseudoobstruction. A rectal tube can be left in place to vent the distal colon in colonic pseudoobstruction and other colonic distension disorders.”
Name conditions for which you might use cautery therapy or vasoconstritors or sclerosing agents.
“Cautery techniques can stop hemorrhage from ulcers, vascular malformations, varices, and hemorrhoids. Endoscopic encirclement of varices and hemorrhoids with constricting bands stop hemorrhage from these sites, whereas endoscopically placed clips can occlude arterial bleeding sites.”
Surgery is curative in ulcerative colitis, whereas in Crohn’s disease it only manages symptoms.
True or False?
True.
When is fundoplication of the gastroesophageal junction performed?
“Fundoplication of the gastroesophageal junction is performed for severe ulcerative esophagitis and drug-refractory symptomatic acid reflux.”
Operations for motor disorders include implanted electrical stimulators for gastroparesis aswell as electrical devices and artificial sphincters for fecal incontinence.
True or False?
True.
