IBS & Diverticulosis Flashcards
What is the most commonly diagnosed GI condition?
IBS.
What is IBS, irritable bowel syndrome?
Recurrent abdominal pain or discomfort associated with two or more of the following:
(1) improvement with defecation
(2) onset associated with change of frequency of stool
(3) onset associated with change of form of stool.
What is the expected decrease is life expectancy when diagnosed with IBS?
No decrease.
What are the 2 main types of IBS?
(1) IBS-C: slow colonic transit
(2) IBS-D: accelerated colonic transit
What is visceral hypersensitivity?
Increased sensation in response to stimuli, perhaps due to an abnormal stimulus or abnormal central pain processing.
Which IBS subtype is more likely to experience an increase in abdominal girth with bloating?
IBS-C.
What is a possible cause of abdominal distention in IBS?
Gas retention due to impaired gas transit.
What are studied associations of bacteria and IBS?
(1) There is an increased risk of IBS after a bacterial (or really any) infection
(2) Treatment of small intestinal bacterial overgrowth reduces IBS symptoms
What are differences in gas production between the 2 subtypes of IBS?
IBS-D has higher hydrogen and negligible methane. IBS-C has both hydrogen and methane.
What are FODMAPs?
Fermentable (by colonic bacteria) oligosaccharides, disaccharides, monosaccharides and polyols. They are associated with the induction of IBS symptoms.
What is a possible way of determining which foods should be eliminated from the diet in order to improve IBS symptoms?
Remove those foods for which there are high IgG titers in the serum.
Which other GI disorder has an association with IBS?
Celiac disease. Gluten-free diets can improve the symptoms of some IBS patients (more IBS-D than IBS-C).
What type of immune cell is most notably increased in IBS?
Mast cells.
What psychosocial factors are associated with IBS?
Increased abuse, stress, anxiety, depression are risk factors for IBS.
What is diverticulosis?
Refers to the presence of diverticula, sac-like protrusions from the colonic wall.
What is the distinction between a false and true diverticulum?
A true diverticulum contains all layers of the colonic wall. Most diverticula are false.
Where are diverticula typically located?
The descending and sigmoid colon.
What is the pathogenesis of diverticulosis?
Increased elastin deposition leads to thickened teniae coli, a high contractility, and thickened circular muscle. This leads to decreased luminal diameter and increased intraluminal pressure. At the same time, increased collagen and collagen cross-linking leads to increased rigidity, thus an impaired ability to accommodate the increase in pressure.
What changes in neurotransmitter production influence diverticulosis?
Increases in serotonin and acetylcholine and decreases in NO and VIP lead to increased motility and intraluminal pressure.
What profile is at increased risk of diverticulosis?
An obese, elderly individual with low physical activity and a low-fiber, high-fat, high-red meat diet.
What is diverticulitis?
Inflamed diverticulosis.
What is SCAD?
Segmental colitis associated with diverticulosis. It is a form of diverticulitis and may be a precursor to IBD.
What is SUDD?
Symptomatic uncomplicated diverticular disease. Symptoms of diverticulosis without overt macroscopic colitis or diverticulitis.
What is the pathogenesis of diverticulitis and its complications?
(1) Erosion of the colonic wall
(2) Inflammation
(3) Focal necrosis
(4) Perforation leading to obstruction, fistula, or peritonitis
What is the pathogenesis of diverticular bleeding?
(1) As the diverticulum herniates, the vasa recta that supplies blood becomes exposed in the lumen
(2) Segmental weakness of the artery
(3) Rupture
