IRRITABLE BOWEL SYNDROME (IBS) | Questions & Answers (100 %Score) Latest
Updated 2024/2025 Comprehensive Questions A+ Graded Answers | 100% Pass
Irritable Bowel Syndrome - Definition - ✔✔Syndrome of symptoms including chronic abdominal pain
and irregular bowel movements in the absence of structural abnormalities
Bowel Habit Subtype Classifications - ✔✔IBS with constipation, IBS with diarrhea, Mixed IBS
Etiology of IBS - ✔✔Unknown. Stress? Psychological (conscious vs. unconscious). Physical (enterocolitis)
IBS - interplay between physical and psychological - ✔✔IBS = higher incidence of anxiety and
depression. What started as physical insult became psychological burden
Hallmark Pathophysiology of IBS - ✔✔Visceral hypersensitivity
Brain-Gut Axis - ✔✔Brain has been shown to influence the gut. High correlation of GI symptoms with
psychological distress. Somatization (fibromyalgia, interstital cystitis, chronic fatigue syndrome) = seen
in some IBS patients
fMRI of IBS patients - ✔✔After rectal distention - amygdala and anterior cingulate light up in IBS patients
vs. prefrontal cortex and thalamus in normal controls. Limbic part of the brain (emotions) tends to react
more in IBS patients
Enteric Nervous systemic - ✔✔5HT serotonin receptors. ENS is in constant contact with the CNS
Presumed pain mechanism in IBS - ✔✔Gaseous distention + visceral hypersensitivity (pain fibers in gut
are stretch receptors)
Intestinal Gas in IBS - ✔✔Study showed that patients with IBS have impaired transit of gas (found gas
pockets) and decreased tolerance of intestinal gas
Updated 2024/2025 Comprehensive Questions A+ Graded Answers | 100% Pass
Irritable Bowel Syndrome - Definition - ✔✔Syndrome of symptoms including chronic abdominal pain
and irregular bowel movements in the absence of structural abnormalities
Bowel Habit Subtype Classifications - ✔✔IBS with constipation, IBS with diarrhea, Mixed IBS
Etiology of IBS - ✔✔Unknown. Stress? Psychological (conscious vs. unconscious). Physical (enterocolitis)
IBS - interplay between physical and psychological - ✔✔IBS = higher incidence of anxiety and
depression. What started as physical insult became psychological burden
Hallmark Pathophysiology of IBS - ✔✔Visceral hypersensitivity
Brain-Gut Axis - ✔✔Brain has been shown to influence the gut. High correlation of GI symptoms with
psychological distress. Somatization (fibromyalgia, interstital cystitis, chronic fatigue syndrome) = seen
in some IBS patients
fMRI of IBS patients - ✔✔After rectal distention - amygdala and anterior cingulate light up in IBS patients
vs. prefrontal cortex and thalamus in normal controls. Limbic part of the brain (emotions) tends to react
more in IBS patients
Enteric Nervous systemic - ✔✔5HT serotonin receptors. ENS is in constant contact with the CNS
Presumed pain mechanism in IBS - ✔✔Gaseous distention + visceral hypersensitivity (pain fibers in gut
are stretch receptors)
Intestinal Gas in IBS - ✔✔Study showed that patients with IBS have impaired transit of gas (found gas
pockets) and decreased tolerance of intestinal gas