Constipation Diarrhoea and IBS

Question 1

is constipation a disease

Answer 1

no it is not, mainly considered a symptom

Question 2

some symptoms of constipation

Answer 2

Fewer than three bowel movements a week
Stools that are hard, dry, or lumpy Stools that are difficult or painful to pass
A feeling that not all stool has passed

may last for a short or long time and bowel patterns may vary

Question 3

people more at risk of constipation

Answer 3

Women approx. 4 times more likely than men,
▪ especially during pregnancy
▪ after giving birth

older adults

non-Caucasians non-Hispanic blacks were twice as likely as non-Hispanic
whites

those who eat little to no fibre

those taking certain medicines or dietary supplements

those with certain health problems, including functional gastrointestinal disorders

women more likely due to hormonal factors and fluctuations during pregnancy, menstruation cycle…etc
note that againg may reduce gut motility, thereby resulting in constipation

Question 4

how many types of stools according to bristol stool chart

Answer 4

7
Types 1 and 2 indicate
constipation.

Types 3 and 4 are the
easiest to pass.

Types 5-6 are more
symptomatic of diarrhea.

Type 7 may be a sign of
cholera or food
poisoning, etc.

Question 5

constipation complications

Answer 5

haemorrhoids,
faecal impaction,
faecal impaction with spurious overflow,
urinary incontinence,
bladder outlet obstruction,
urinary tract infection,
rectal bleeding,
general weakness
psychological disorders

Hemorrhoids, also known as piles, are swollen veins in the anus and rectum that can cause discomfort

Fecal impaction is the result of constant constipation when poop is stuck inside of your rectum.

Question 6

the Problems associated with Persistent straining in constipation leads to

Answer 6

increased intrathoracic pressure

a reduction in coronary and peripheral circulation

development of hernias

worsening of gastro-oesophageal reflux

transient ischaemic attacks (mini strokes, where blood flow to brain is reduced.)

A hernia occurs when an internal part of the body pushes through a weakness in the muscle or surrounding tissue wall

Question 7

causes of constipation

Answer 7

conditions like coeliac disease, multiple sclerosis, cystic fibrosis…etc

hypothyroidism

some medications like opiods and antacids

low fibre intake

inadequate fluid intake

pelvic floor dysfunction

physical inactivity…etc

Coeliac disease is a chronic autoimmune disorder that occurs when the body’s immune system attacks the small intestine in response to gluten

Cystic fibrosis is an inherited condition that causes sticky mucus to build up in the lungs and digestive system

Question 8

fibre functions(foods high in wheat grains, oats, or fruits & vegetables)

Answer 8

Bulks Up Stool: Fiber adds bulk to stool, which makes it easier to pass through the intestines. This helps prevent constipation and promotes regular bowel movements.

Stimulates Bowel Movements

feedsd gut microbiome…etc

we have soluble and insoluble fibres

Question 9

non- pharmacological treatments to constipation

Answer 9

dietary adjustments, like taking in more fibres and fluids

oral rehydration solutions

rest and stress management

using natural probiotics or probiotic supplements

avoiding foods that cause it

increasing physical activity

Probiotics are live microorganisms promoted with claims that they provide health benefits when consumed, generally by improving or restoring the gut microbiota. generally safe ti consume

Question 10

pharmacological treatments to constipation

Answer 10

Laxatives

Anti-Diarrheal Medications, like loperamide and Bismuth Subsalicylate

prucalopride

Prokinetic Secretagogues

Question 11

laxatives

types?

Answer 11

medicines that treat constipation by making stools softer or easier to pass

osmotic
stimulant
bulking

only use laxatives after lifestyle modifications, supplements and emollients or stool softners have been tried

Question 12

how bulk laxatives work

Answer 12

The fibers in these laxatives absorb water like a sponge. When you ingest a bulk laxative, it takes in water from the intestines, which causes it to expand. As it swells, it increases the size of the stool inside the colon.
As the stool becomes bulkier, it stretches the walls of the intestines, stimulating peristalsis

works more gently compared to other 2 types.

Question 13

are bulk laxatives soluble or absorbable from the intestines

are they excreted intact

Answer 13

no
They remain intact as they move through the digestive system, so they can directly affect stool consistency and volume

Yes, while some of the fiber may undergo fermentation by bacteria, much of the bulk-forming agent, especially the fiber like ispaghula husk, is excreted largely intact in the stool. This is actually one of the key features of how it works — it provides bulk and absorbs water in the intestines, but doesn’t get broken down, allowing it to have that beneficial effect on stool consistency.

Question 14

composition of bulk laxatives

Answer 14

a special fibre called arabinoxylan a complex carbohydrate with a backbone made of xylose and side branches containing arabinose sugars.

these enhance it’s water absorbing properties

Question 15

bulk laxatives are often referred to as muciliganous fibres, why is this

Answer 15

because of their ability to form a gelatinous or gel-like mass when they absorb water. This gel further softens the stool and holds water within it, which is essential for preventing constipation and easing stool passage.

Question 16

how are bulk laxatives digested

Answer 16

a small amount is fermented by faecal bacteria in our intestines, and the rest is excreted intact

the fermentation process can sometimes lead to flatulence and gas a by product

Question 17

how do bulk laxatives affect the structure of the GI tract, consequently increasing peristalsis

Answer 17

Increased bulk adds extra weight to the material in the gut- generating more stretch of the gut wall

Stimulates stretch receptors

Activates ‘mechanoreceptors’

Leads to release of acetylcholine

ACh causes contraction of the intestines

Peristalsis is increased

Transit rate is increased

Transit time is reduced

The speed at which material moves through the GI tract.
The total duration it takes for material to travel through the GI tract.

Question 18

describe the action of mechanoreceptors(like stretch receptors) that lead to an increase in peristalsis

Answer 18

they induce a neuronally mediated reflex contraction of the intestinal smooth muscle, while causing a descending relaxation of the smooth muscle.
This propulsion allows fecal matter to
move in the direction of the anus for
evacuation

Question 19

surfactant laxatives and how they work

Answer 19

anionic detergents that lower the surface tension of stools, thereby softening the stool and enabling **water and lipid penetration into the faecal mass **

not effective for severe constipation, good for mild constipation

aka stool softners , they take 1-3 days to work

tenesmus (the feeling of needing to pass stool even though bowels are empty) is avoided when using these

Question 20

is there is direct stimulation of peristalsis when using surfactant laxatives

Answer 20

no there is not

Question 21

what is meant by straining in constipation

Answer 21

straining refers to the excessive effort or force applied during defecation to expel hard or compacted stool. This involves increased abdominal pressure through strong contraction of the abdominal and pelvic muscles.

Question 22

in what instances should surfactant laxatives be used

Answer 22

They are commonly used in situations where straining should be avoided, such as:
Post-surgery
Hemorrhoids
Recovery from myocardial infarction..etc

Question 23

osmotic laxatives and how they work

Answer 23

are a class of laxatives that promote bowel movements by drawing water into the intestines, softening the stool, and increasing its bulk to stimulate peristalsis (intestinal muscle contractions).

Question 24

examples of osmotic laxatives

Answer 24

macrogol
lactulose
Magnesium hydroxide or magnesium sulphate

Question 25

macrogol, what it is and how it works

Answer 25

A high molecular weight polyethylene glycol

is a non-absorbable polymer that retains water in the stool through osmotic action.

It increases stool volume and softens stool without causing significant electrolyte shifts

Treatment of chronic constipation.

aka polyethylene glycol

May take 1–2 days for effects at lower doses

Question 26

lactulose, what it is and how it works

Answer 26

a synthetic disaccharide that is not absorbed in the small intestine.

lowers pH of the colon
increases osmotic pressure within the colon, drawing water into the colon.
increases stool water content

Useful in both constipation and hepatic encephalopathy

Can cause bloating, flatulence, and cramping due to bacterial fermentation

Question 27

how is lactulose broken down in the colon

Answer 27

colonic bacteria breaks down lactulose into lactic acid, acetic acid and formic acid, lowering colon pH and increasing osmotic pressure in the colon

Question 28

how is an acidic environment beneficial to the colon (normally alkaline)

Answer 28

Hepatic encephalopathy: Reduces ammonia levels by converting it to ammonium (NH4+), which is excreted in the stool. This reduces ammonia levels in the blood, protecting against neurotoxicity.

The acidic environment favors the growth of beneficial bacteria like Lactobacilli and Bifidobacteria.

Suppression of Pathogenic Bacteria

Question 29

Magnesium hydroxide or magnesium sulphate, what it is and how it works

Answer 29

Magnesium sulfate (Epsom salt) and magnesium hydroxide (milk of magnesia) are poorly absorbed in the gut.
They create an osmotic gradient in the intestines, pulling water from the surrounding tissues into the intestinal lumen.
This increases the volume and water content of the stool, softening it and making it easier to pass.
The increased stool volume stretches the intestinal walls, triggering mechanoreceptors.
This stimulates peristalsis (rhythmic contractions of the intestinal muscles), propelling the stool forward.

it’s Magnesium ions may stimulate the release of the hormone cholecystokinin (CCK)

it also increases osmotic pressure of the stool

Question 30

CCK is a hormone

some CCK functions in the gut essential to it’s function as a laxative

Answer 30

Enhances intestinal motility.

Increases fluid and electrolyte secretion, further aiding in bowel movements.

Question 31

the inactive susbtance in senna(a stimulant laxative)

they are metabolised into an active metabolite known as ? by what?

Answer 31

sennosides

rheinanthrone , by gut bacteria

Question 32

how does rheinanthrone act on the myeintric plexus

Answer 32

by;
stimulating peristalsis, increases force and rate of contractions

inhibiting local contractions within the colon, (haustrations)

these actions together reduce fluid absorption from the stool.

Question 33

describe the mechanism by which senna reduce water reabsorption within the colon

what is another way that senna can increase water content in the lumen of the large intestine

Answer 33

increases
cyclooxygenase 2 (COX2)
expression in macrophage cells, leading to;
an increase in prostaglandin E2.

this causes a decrease in aquaporin 3 expression in mucosal epithelial cells of the large intestine

results in a reduction of the water reabsorption within the colon, thereby an increase in stool water content

by rheinanthrone acting on submucosal cholinergic neurons, resulting in increased chloride
secretion in the large intestines. This draws water into the large intestines(osmosis)

Question 34

name some prokinetic secretagogues

Answer 34

Lubiprostone

Linaclotide

Plecanatide

Question 35

linaclotide mechanism of action

Answer 35

Binds to Guanylate Cyclase-C (GC-C) Receptors

Increases cGMP(secreted extracellularly)

Intracellular cGMP stimulates the cystic fibrosis transmembrane conductance regulator (CFTR) channel.

increased Cl- and HCO3- secretion

The secretion of chloride and bicarbonate creates an osmotic gradient, drawing water into the intestinal lumen.

This softens stool and increases stool volume, promoting easier bowel movements.

it is a Guanylate cyclase C (GC-C) agonist

Question 36

Lubiprostone mechanism of action

Answer 36

it activates Chloride channels in the intestines, which leads to efflux of Cl- into the lumen(primary effect of the drug)

efflux of Na+ ions, following the chloride efflux

increased salt concentration

water secretion into the lumen of the large intestines, due to the osmotic gradient created

Results in softening the stools

it is classed as a Locally acting Cl- channel activator

Question 37

prucalopride, what it is, and

it’s mechanism of action

Answer 37

Highly selective and potent 5HT4 receptor agonist
it is absorbed into the systemic circulation, where it stimulates gut motility.

Acts on presynaptic 5HT4 receptors on myenteric cholinergic nerve terminals
▪ enhances the fast excitatory synaptic signals
▪ increase the parasympathetic system induced contractions of the
intestine.
▪ enhances the occurrence of mass movements
▪ accelerates propulsion of material in the colon.

it basically enhances gut movement