constipation

Question 1

symptoms of constipation

Answer 1

• fewer than 3 bowel movements per week
• straining
• lumpy hard stools
• sensation of anorectal obstruction
• sensation of incomplete defaecation
• manual manoeuvring required to defaecation

Question 2

primary constipation

Answer 2

• normal-transit constipation
• slow-transit constipation
• pelvic floor dysfunction
• irritable bowel syndrome with constipation

Question 3

secondary constipation

Answer 3

• medications
• metabolic disorders
• endocrine disorders
• psychiatric (anxiety/depression)

Question 4

mechanism of drug-induced constipation

Answer 4

• drugs with anticholinergic activity: antidepressants, antihistamines, antipsychotics, antiparkinsonian agents
• opioids
• drug affecting electrolytes
• laxative misuse - leads to atonic colon

Question 5

treatment of constipation

Answer 5

• laxatives (osmotic/stimulant/bulk-forming/faecal softeners)
• drug treatment: used in constipation associated with IBS and chronic idiopathic constipation

Question 6

linaclotide

Answer 6

• used for constipation of moderate to severe
• 14 amino acid synthetic peptide
• linaclotide activates guanylate cyclase C (enzyme)
• increases cellular cGMP )second messenger) which activates protein kinase G
• phosphorylation of Cl- channel in the enterocyte membrane leads to secretion of chloride
• increased efflux of Cl- (and water)
• restricted use (not approved by scottish mc)

Question 7

lubipprostone

Answer 7

• member of a class of agents called prostones
• derived from functional fatty acids that occur naturally
• binds directly to Cl- channel
• increases secretion of Cl- and water
• some research suggests it has restorative properties of the mucosal barrier

Question 8

adverse effects of linaclotide and lubipprostone

Answer 8

• generally well tolerated
• diarrhoea
• nausea
• vomiting
• abdominal pain