ICL 15.2: IBS and Constipation

Question 1

what are functional gastrointestinal disorders?

Answer 1

FGIDS are disorders, not a disease!!

they’re functional disorder so there’s not structural or biochemical abnormalities which means there will be normal x-rays, blood tests and endoscopies

they can affect any part of the GI tract

considered a disorder of the mind gut axis

Question 2

what are the most common functional gastrointestinal disorders?

Answer 2

1. irritable bowel syndrome

altered bowel habits combined with abdominal pain/bloating that’s usually relieved with BM

2. functional dyspepsia

ulcer-like symptoms with upper-GI pain/indigestion/discomfort/fullness +/- nausea, soon after eating

Question 3

who is affected by IBS?

Answer 3

affect 5-20% of population

females > males (1.5-2:1)

younger > Older (50% <35 y/o)

affects lower socioeconomic groups more

PCP: 12%, GI practices : 28% - 50%

Question 4

how do you diagnose iBS?

Answer 4

Rome criteria

recurrent abdominal pain, on average of at least 1 day per week in the last 3 months, associated with two or more of the following:

1. pain with defecation
2. onset associated with a change in frequency of stool
3. onset associated with a change in form of stool

criteria needs to be fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

Question 5

what is the pathophysiology of IBS?

Answer 5

PSYCHOSOCIAL FACTORS
1. life stress

2. psychologic state
3. coping ability
4. social support

PHYSIOLOGY
1. motility

2. sensation

EARLY LIFE
1. genetics

2. environment

FGID
1. sypmptom experience

2. behavior

patients have more sleep issues and somatic pain which all leads to a decreased quality of life and they’re hard to manage because there’s so many different components to try to have to manage because you have to manage the whole brain-gut axis

Question 6

how are IBS patients hypersensitive?

Answer 6

if you post a balloon in their colon they’ll be more uncomfortable but the same happens when you put their hand in an ice bucket so they’re just really hypersensitive

also if you put the balloon in different parts of the colon, they have referred pain in larger areas of their abdomen in comparison to normal people

so they’re just really hypersensitive to pain so they report pain more often than normal patients with the balloon insertions

Question 7

what are the subtypes of iBS?

Answer 7

they’re based on stool consistency

IBS-C = constipation predominant IBS

IBS-D = diarrhea predominant IBS

IBS-M = mixed-IBS with both diarrhea and constipation

IBS-U = unclassified IBS

Question 8

what are the different types of stool consistency?

Answer 8

type 1 = separate hard lumps = severe constipation

type 2 = lumpy and sausage like = mild constipation

type 3 = sausage shape with cracks in the surface = normal

type 4 = smooth, soft sauce or snake = normal

type 5 = soft blobs with clear cut edges = lacking fibre

type 6 = mushy consistency with ragged edges = mild diarrhea

type 7 = liquid consistency with no solid pieces = severe diarrhea

IBS-D has types 5-7 more than 25% of the time and IBS-C has types 1 and 2 and IBS-M it has both

Question 9

what is the clinical presentation of IBS?

Answer 9

1. chronic abdominal pain
2. bloating
3. altered bowel habits

in the absence of red flags***

Question 10

what are the red flags that would make something not IBS?

Answer 10

1. unintended weight loss
2. blood in the stools not caused by hemorrhoid or anal fissures
3. abnormal labs = anemia, hypoalbuminemia, liver tests, elevated CRP or ESR
4. fever
5. family history of GI cancer, IBD or celiac disease

Question 11

how do you workup someone who you think has IBS if there aren’t alarm signs?

Answer 11

1. PE
2. complete blood count
3. stool for occult blood
4. routine colorectal cancer screening if over 50
5. blood tests
6. fecal calprotectin
7. check stool of C/S, ova and parasites if they’re having diarrhea
8. diagnostic colonoscopy if poor response to treatment

CT scans should not be routinely performed in iBS patients unless they have alarm features

Question 12

what characteristics of a patient presentation would suggest that they don’t have IBS?

Answer 12

1. onset in old age
2. steady progressive course
3. frequent awakening by pain
4. weight loss not attributed to depression

Question 13

what do you need to do to diagnose IBS-D?

Answer 13

1. stool cultures: little role in chronic diarrhea (except for Giardia).
2. celiac disease: screening with serum TTG IgA
3. 24 hour stool collection: if osmotic, secretory or malabsorptive diarrhea is suspected
4. colonoscopy or flexible sigmoidoscopy & biopsy: rule out microscopic colitis
5. radiography: a plain film of the abdomen can detect retained stool, (constipation)

Question 14

which diseases mimic IBS-D?

Answer 14

I = intolerances, especially carbohydrates

B = bacterial overgrowth/dysbiosis

S = sprue and maybe gluten sensitivity

D = drugs, alcohol and laxative

Question 15

what is post-infectious IBS?

Answer 15

20% of IBS patients describe acute infectious prodrome

occurs in 5-25% after bacterial enteritis and is mostly diarrhea predominant

can occur after most after most enteric pathogens (bacterial & viral) and after antibiotic treatment

more common in females

long duration of diarrhea (eventual resolution not certain but more likely than in non-PI-IBS)

occurs in subjects with anxiety, depression

Question 16

what does CIC stand for?

Answer 16

chronic idiopathic constipation

no reliable radiologic, endoscopic, biomarkers abnormalities…

Question 17

what is chronic idiopathic constipation?

Answer 17

infrequent or difficult evacuation of stool

normal stool frequency is three times weekly to as frequently as twice daily so infrequency is two or fewer times a week

difficult evacuation, less clearly defined but encompasses inability to initiate or complete evacuation, excess straining, or feeling of incomplete evacuation

hard stool definition varies and is subjective… but it’s stool that’s physically hard or hard to pass

Question 18

how is stool formed?

Answer 18

approximately 1L fluid daily reaches the cecum:

derived of water, insoluble fiber and salts

during the next 24-30hrs 90% of water and salts are reabsorbed

fiber is fermented into gas

yield is 80-120g/24hrs feces

Question 19

how does the gut move?

Answer 19

phasic contractions and background contractility

there are high amplitude propagated contractions contribute to mass movements

parasympathetic (+)

sympathetic (-)

external Sphincter is voluntary

ascending and transverse colon act as depot for stool

transit ~12 hours/segment

Question 20

what is the pathophysiology of CIC?

Answer 20

it’s due to altered signalizing in the GI tract!!
1. defects in mucosal serotonin/ACh

2. altered numbers of EC cells
3. altered levels of serotonin transporters

this all leads to altered GI physiology like altered motility, altered sensitivity, and altered secretion which can result in chronic constipation or IBS-C

Question 21

what populations are moe likely to have constipation?

Answer 21

1. females
2. older subjects (increases with age)
3. lower socioeconomic status.
4. linked to impaired quality of life

Question 22

what are the 2 posible categories of constipation?

Answer 22

IDIOPATHIC
1. slow transit constipation

2. functional outlet
3. obstruction
   obscure

SECONDARY
1. metabolic

2. endocrine
3. smooth muscle isorders
4. CNS Disorders
5. peripheral nervous
   system Disorder
6. stenosis/obstruction
7. painful anal lesions

RULE OUT THE SECONDARY CAUSES FIRST!!

Question 23

what are the endocrine causes of constipation?

Answer 23

1. hypothyroidism

2. DM

Question 24

what are the metabolic causes of constipation?

Answer 24

1. hypercalcemia

2. hypokalemia

Question 25

what are the neurologic causes of constipation?

Answer 25

1. Parkinson’s 2. multiple sclerosis 3. spinal cord lesions 4. cerebrovascular accident 5. muscular dystrophy 6. autonomic myopathy

Question 26

what are the rheumatologist causes of constipation?

Answer 26

1. systemic sclerosis

Question 27

what are the psychosocial causes of constipation?

Answer 27

1. depression | 2. eating disorders

Question 28

what are the medication causes of constipation?

Answer 28

1. narcotics 2. anticholinergenics 3. antipsychotics 4. calcium channel blockers 5. anti-Parkinson's therapy 6. anticonvulsants 7. tricyclic antidepressants 8. iron 9. calcium 10. aluminum antacids 11. sucralfate

Question 29

what is the ROME0IV diagnostic criteria for chronic idiopathic constipation?

Answer 29

presence of difficult stool passage with symptoms for 3 months with onset more than 6 months ago during at least 25% of their defections, there must be 2+ of the following: 1. straining 2. lumpy or hard stools 3. sensation of incomplete evacuation 4. sensation of anorectal obstruction/blockage 5. manual maneuvers to facilitate defecation 6. less than 3 delectations per week

Question 30

how do you dignase CIC?

Answer 30

if they meet the ROME-IV criteria then you look for an abnormal balloon expulsion test or abnormal anorectal manometry or anal surface EMG.

Question 31

what is the ROME clinical friendly definition for IBS and CIC?

Answer 31

IBS : abdominal discomfort/pain associated with altered bowel habits CIC: unsatisfactory defecation that is characterized by infrequent stools, difficult stool passage, or both

Question 32

how can you differentiate CIC and IBS-C?

Answer 32

CIC must include 2+: 1. hard or lumpy stool 2. straining 3. incomplete evacuation 4. sensation of anorectal obstruction/blockage 5. manual maneuvers 6. < 3 defecations/week 7. pain not usually present IBS-C recurrent abdominal pain/discomfort with: 1. change in pain with defecation 2. onset associated with change in frequency of stool 3. onset associated with change in form (appearance) of stool

Question 33

what are the different diagnostic tests you can do for IBS or CIC?

Answer 33

1. anorectal manomety 2. balloon-expulsion 3. colonic-transit study 4. defecography

Question 34

what is anorectal manometry and what is it used for?

Answer 34

a pressure-sensitive catheter is inserted into the anus to measure resting and squeeze pressures of the sphincter normally there is an increased pressure in the rectum and decrease in the anal canal as stool moves out but with anorectal dyssynergia there's no increased pressure in the rectum and the anal canal pressure remains elevated assesses the internal and external anal sphincters, pelvic floor, and associated nerves

Question 35

what is a balloon-expulsion test and what is it used for?

Answer 35

a balloon with 50 ml of water or air is inserted into the rectum and then the patient is asked to expel the balloon --> if they expel within 1 minute that's normal and more than 2 minutes is abnormal helps detects defecatory disorders and is a simple, office-based screening test sensitivity 88%, specificity 89%, PPV 67% and NPV 97%

Question 36

what is a colonic-transit study and what is it used for?

Answer 36

the patient swallows a capsule filled with radiopaque markers and then serial abdominal radiographs are taken 120 hours later ingesting 24 plastic markers with xrays on day 1 & day 6 (120 hours) <20% should be present at day 6 it measures rate at which fecal residue moves through colon

Question 37

what is a defecography and what is it used for?

Answer 37

thickened barium is instilled into the rectum and then radiographic films are taken during defecation it detects structural abnormalities of the rectum --> provides useful evaluation of prolapse

Question 38

what is the finger test?

Answer 38

put your finger in someones rectum and feel for something abnormal which means you probably need to do a more invasive modality

Question 39

how do you generally manage iBS?

Answer 39

1. avoid narcotics!! they cause constipation 2. patient education about exercise and stress reduction 3. fiber supplements 4. diet 5. anticholinergic medications 6. avoid antidepressants 7. antibiotics 8. serotonergic tangents and prosecretory agents

Question 40

what are the dietary interventions for iBS?

Answer 40

1. gluten free 2. FODMAP 2. lactose free diet 4. exclusion of gas producing foods = beans, onions, celery, car

Question 41

what is a FODMAP?

Answer 41

fermentable oligo-di- and monosaccharides and polyps huge change in IBS symptoms just by trying a low FODMAP diet! the theory is that there is impaired absorption of the FODMAPS that leads to intestinal fermentation of the carbohydrates by gut bacteria which leads to symptoms and increased intestinal permaeability people who do a low FODMAP diet have improved pain, bloating, passing of satisfaction with stool consistency

Question 42

what is non-celiac gluten sensitivity?

Answer 42

gut and other symptoms that respond to a gluten-free diet; wheat allergies are excluded they do not fulfill criteria for Celiac disease there's no real way of determining that gluten is inducing the symptoms because there's no biomarkers so it's all symptom based and a lot of people feel better when they're put on a gluten free diet up to 13% of the population has some gluten sensitivity! but 20% of these people actually have Celiac

Question 43

what medication do you treat IBS-C with?

Answer 43

Prosecratory: 1. linactolide 2. plecanatide 3. lubiprostone

Question 44

what medication do you treat IBS-D with?

Answer 44

1. rifaximin 550mg tid x 2 weeks 2. ntidepressants: TCAs SSRIs 3. eluxadoline (ópiod derivative) 4. alosetron

Question 45

what medication can you treat any type of IBS with?

Answer 45

antispasmodics: 1. otilonium 2. pineverium 3. hyocine Bromide 4. cimetroprium bromide 5. drotaverine 6. dicyclomine hydrochloride 7. peppermint oil

Question 46

how do you treat CIC?

Answer 46

1. fiber supplements 2. osmotic laxatives 3. stimulate laxatives 4. PEG 5. prosecretory: lubiprostone linaclotide prucalopride

Question 47

what classes of laxatives are there?

Answer 47

1. bulk agents 2. non absorbed substances 3. diphenylmethanes 4. anthraquinone 5. secretory drugs

Question 48

what non absorbed laxatives are there?

Answer 48

1. PEG (polyethylene glycol) | 2. lactulose

Question 49

what bulk agent laxatives are there?

Answer 49

1. psyllium 2. methylcellulose 3. calcium polycarbophil 4. wheat dextrin

Question 50

what anthraquinone laxatives are there?

Answer 50

senna

Question 51

what secretory drug laxatives are there?

Answer 51

1. lubiprostone 2. linaclotide 3. plecanatide

Question 52

what are the benefits of using PEG?

Answer 52

polyethylene glycol improves stool frequency only in CIC may not alleviate abdominal pain

Question 53

what are the benefits of using lubiprostone? what are the side effects and MOA?

Answer 53

selectiveC-2 chloride channel activators so it releases a bunch of Cl into the glut which is then followed by water which drives stool motility relief of IBS symptoms in female IBS-C patients may cause nausea, diarrhea, abdominal pain, and headache, teratogenic risks

Question 54

what are the benefits of using linaclotide? what are the side effects and MOA?

Answer 54

guanylate cyclase agonists which drives HCO3 excretion which is also followed by water --> on the nonluminal side it induces NO which relaxes the nerve and helps with IBS-C pain! relief symptoms of IBS-C long-term risks are unknown, severe uncontrolled diarrhea

Question 55

what are the benefits of using prucalopride? what are the side effects and MOA?

Answer 55

5-HT4 receptor agonist relief of symptoms of CIC suicidal ideation, nausea and diarrhea

Question 56

how do you treat long term CIC?

Answer 56

subtotal colectomy for colonic intertia this is only for patients with severe intractable and disabling symptoms they can't have evidence of intestinal pseudo-obstruction and must have anorectal function

Question 57

how do you workup refractory constipation?

Answer 57

when you start a patient on treatment for CIC, start with fibers and laxatives first then you do anorectal manometry and balloon expulsion test and if both are normal you look at clonic transit -- if it's slow you see if you can medically manage it or if you need a partial colectomy but if they're normal then it's IBS-C --> if they're abnormal then you refer to biofeedback which teaches the pelvic floor how to respond properly which usually helps a lot of people --> if the two tests don't match do defecography to figure out specifically where is messed up

Question 58

what is biofeedback treatment for CIC?

Answer 58

for pelvic floor dysfunction (dyssynergia). biofeedback, performed by a trained and skilled therapist

Question 59

how do you medically and dietary treat IBS-D?

Answer 59

DIETARY 1. gluten free 2. low FODMAP MEDICATION 1. tricyclics 2. rifaximin 3. eluxadoline

Question 60

what is eluxadoline?

Answer 60

Mu and Kappa agonist, delta antagonist so it acts like an opioid without giving the high good for treating IBS-D contraindication: patients at risk for pancreatitis or have had their gallbladder removed

Question 61

if someone has chronic constipation what is the differential and how would you treat each?

Answer 61

1. slow transit/functional constipation --> treat with linaclotide, lobiprostone, prucalopride, PEG, or laxatives 2. IBS-C normal transit --> treat with llinaclotide, lobiprostone, SSRI, or laxatives 3. dyssynergic defecation --> biofeedback therapy

Question 62

what drugs are used for iBS-C treatment?

Answer 62

1. linaclotide* 2. lubiprostone* 3. CBT/hypnotherapy 4. diet modification 5. SSRIs 6. probiotics 7. elobixibat

Question 63

what drugs do you use to treat IBS-D?

Answer 63

1. CBT/hypnotherapy 2. diet 3. rifaximin* 4. TCAs 5. enterra-GAM* 6. eluxadoline* 7. alosetron* 8. probiotics 9. IBgard