Lower GI (Diarrhoea, constipation, IBS, gastroenderitis)

What are the three types of primary constipation?

fucntional
Slow transit
Pelvic floor dysfunction

What is the optimal fiber intake for Man and women?

Man 30-39g
women 21-25g

What is the criteria of functional constipation?

2 or more of these for over 3 months
straining >255
Lumpy Bristol 1-2 >25%
Incomplete sensation >25%
sensation of anorectal obstruction >25%
Bowel

Secondary constipation?

GI disorder
cardiac disorder (HF)
Lifestyle
Pregnancy (physio and taking Iron salts)
Metabolic disorders (diabetes)
Neurologic

What are the classes of drugs that can cause constipation?

Analgeics : Opioids
Anticholinergics
Antacids (Ca, Al salts)
CCB
Diuretics
Iron supplements
Muscle blockers
NSAIDs (celecoxib)

Red flags for constipation referral?

New onset in elderly with no reason
melaena
family history of colon cancer
weight loss
severe constipation
nausea and vomiting

What are the agents used to treat constipation? (non-prescription)

Bulk-forming agents (first)
(increase water content to it, methylcellulose, psyllium hydrophilic colloid)

Osmotic agents (Glycerin (suppository), lactolose, PEG)

Stool softeners (facilitate mixing of fatty and water content, Docusate. More used in prevention, and post-MI)

Stimulant laxatives (Stimulate mucosal nerve plexus, Senna, anthraquinone, reserved for patient who don't respond to bulk-forming and osmotic)

What are the agents used to treat severe constipation (prescription)?

Intestinal secretagogues

Chloride channel activators
Lubiprostone 24mcg BD
-failed firstline osmitic
- to release Cl rich intestinal fluids, soften stool and incrase GI transit time

Guanylate cyclase-C receptor antagonist
Plecanatide
- stimulate intestinal fluid secretion and transit

Opioid receptor antagonist
Methylnaltrexone
- peripherally acting, doesn't cross BBB- used in opioid induced constipation
- SC administered.

Most common bacteria that causes food poisoning?

Bacillus Cereus
Staphyloccus aureus
Enterotoxigenic Ecoli (ETEC)
Salmonella spp

Most common bacteria or virus that causes gastroenteritis?

MOstly virus
>90% Notovirus
Infant and children (rotavirus, vaccine)
Astovirus, pestivirus, enterovirus

Most common bacteria that causes traveller diarrhoea?

ETEC
salmonella
campylobacter spp
Shingella spp

Most common bacteria that causes dysentery?

Shingella spp
Salmonella spp
campylobacter spp
EHEC
clostridium difficile

What are the types of diarrhoea?

Osmotic (lactose intolerance, unabsorbed solutes)

Secretory (enteric rotavirus infection, disruption of epithelial electrolyte transport)

Exudative (mucus, blood, IBD, inflammatory disease dysentery)

Altered motility (increase peristalsis, bacteria overgrowth due to omeprazole use pH increase

What is the non-pharm management of diarrhoea?

Oral rehydration therapy (first-line and primary treatment of diarrhoea)
Sodium cholride
Glucose
Potassium chloride
citrate/bicarbonate/trisodium
Osmolarity 245

WHO also recommend add on Zinc 20mg for 10 days

What are the agents used in treating acute diarrhoea?

1. Opiates and derivatives
Loperamide (opoid agonist)
- antimotility, antisecretory
- inhibit calcium binding protein calmodulin

Diphenoxylate (lomotil)
- opioid agonist
- for those who are poorly responsive to loperamide
- added with atropine (to make you sick deliberately)
- acts centrally and peripherally crosses the BBB

2. Absorbents
- activated charcoal (effectiveness not proven)

3. Antisecretory agents
- bismuth subsalicylate
- anti-inflammatory, anti-bacterial, abti-secretory

What agents are use in treating traveller's diarrhoea?

starting with fluid replacement
Loperamide (w/o loody or bloody)
Single dose Fluroquinolone (antibiotic) up to 3days
SEA Azithromycin
Rifazimin, 3 days course of ciprofloxacin

What is IBS?

Abdominal discomfort associated with altered bowel habits

likey cause: visceral hypersensitivity

What is the manning criteria for IBS?

Chronic recurrent abdominal pain for at least 6 months and two or more of the following:
Abdominal pain relieved with defecation
Abdominal pain associated with more frequent stools
Abdominal pain associated with more loose stools
Abdominal distention
incomplete sensation
mucus in stool

What is the Rome IV diagnostic criteria for IBS?

Recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months, 2 or more of the following:
Relieved with defecation
onset associated with change in frequency of stool
Onset associated with a change in form appearance of stool

What are some non-pharm treatment for IBS?

Diet
- avoid FODMAP
- reduce fructose

What are some possible pharmaco treatment for IBS?

Antispasmodics
- peppermint oil
- Alverine, mebeverine
- BY inhibiting Ca2= influx into the intestinal smooth muscle

Antidepressants
- Selectiev 5 HT reuptake inhibitor (SSRI, fluoxetine, citalopram)
- Tricyclic antidepressants

What is the pharmacotherapy of IBS-C?

Lubiprostrone (secretagogoue, chloride channel agonist)

What is the pharmacotherapy of IBS-D?

Antibiotic

Rifaximin (3 day course of ciprofloxacin)