bowel regimens

Strategy

  • Start with Miralax and senna-docusate once a day each
  • Avoid lactulose if bowel is in colon as they will just sit there, absorb water, expand, and cause perforation
  • Use manual disimpaction if bowel in rectum
  • Can use dulcolax or lactulose suppository
  • Use suppository next
  • Use enema last
  • Lactulose enema does not cause perforation
  • Avoid electrolyte enema in renal patients: milk of magnesia, sodium phosphate
  • Avoid anything rectal with leukemia patient

bulk forming laxative

  • mechanism: absorb water, increase stool mass
  • side effects: gas, bloating
  • fiber supplements
  • Metamucil: psyllium seed
  • Citrucel: methylcellulose
  • Fibercon: calcium polycarbophil
  • Benefiber: wheat dextrin

surfactants

  • mechanism: lower surface tension of stool, allows water to enter
  • cons: less effective
  • Colace: docusate sodium
  • docusate calcium

osmotic laxatives

  • mechanism: causes intestinal water secretion
  • side effects: bloating, volume overload, electrolyte disturbance
  • Miralax/GoLytely: PEG, no need to use more than once a day
  • Lactulose: synthetic disaccharide.
  • Sorbitol: similar to lactulose
  • Saline laxative: high magnesium, poorly absorbed, acts as hyperosmolar solution but use with caution for renal insufficiency patients
    • milk of magnesia
    • mag hydroxide
  • glycerin/Glycerol

stimulants

  • mechanism: increase contraction, stimulates sensory nerves, quickest acting, 8-12 hours
  • SE: gastric irritation, melanosis coli with senna
  • Dulcolax: bisacodyl
  • Senokot: senna

disimpaction

  • manual

suppository

  • small pill injected in the rectum
  • can liquidify stool and overcome obstruction
  • glycerin
  • Dulcolax: bisacodyl

enemas

  • liquid injected in rectum
  • soapsuds: soap with water
  • tap water: good for older adults because safer than sodium phosphate enema
  • saline enema
  • milk & molasses
  • mineral oil enema, used usually after disimpaction. Softens stool and provides lubrication
  • sodium phosphate enema: associated with hypotension, hypoCa, hyperP, hypo/hyperK

secretagogue

  • Lubiprostone: type 2 chloride channel activation, cause chloride to move into colon, ionic gradient
  • Linaclotide/plecanatide: CGMP activation, chloride release

opioid antagonist

  • naloxegol, oral naldemedine, SQ methylnaltrexone