Diarrhea

Question 1

Definition of diarrhea

Answer 1

• frequent loose stools with urgency
• passage of > 3 unformed stools (Bristol 5-7) in 24 hours
• > 3 weeks is chronic

Question 2

Causes of diarrhea in palliative care

Answer 2

• Medications
  
  • laxatives
  • antacids
  • antibiotics
  • chemotherapy
  • NSAIDS
  • iron
  • immunotherapy
  • sorbitol
• MBO / fecal impaction
  
  • stool leakage past obstruction
• Cancer treatment
  
  • 5 FU
  • capecitabine
  • irinotecan
  • interleukin therapy
  • targeted therapioes erlotinib, gefitinib etc.
  • epidural growth factor receptor drugs
• Radiation treatment
  
  • 2-3 weeks
  • damage to intestinal mucosa - release prostaglandins
  • increase peristalsis
• Graft vs Host
• Celiac plexus blockage – common cause diarrhea
• Malabsorption
  
  • pancreatic cancer
  • gastrectomy
  • ileal resection
  • colectomy
• Tumour
  
  • colonic / rectal
  • pancreatic islet
  • carcinoid tumours
• Concurrent disease
  
  • DM, Hyperthyroid, IBD, IBS
• Diet

Question 3

Examination and investigations in Diarrhea

Answer 3

• DRE
• abdominal palpation
• Xray
• stool osmolality, na, K
• Osmotic diarrhea :
  
  • > 50 mmol/L
  • prescence of additional solute not absorbed
• Secretory diarrhea
  
  • < 50 mmol/L
  • active secretion of fluid and lytes
• CBC/CH6
• stool culture for salmonella, shigella, campylobacter, viral
• C diff (quinolones and cephalosporins)

Question 4

Assessment for diarrhea

Answer 4

• frequency
• nature of stools
• time course
• current/ recent medications
• pyrexia
• blood
• cytotoxic chemotherapy
• neutropenic enterocolitis
  
  • perforation, septicemia

Question 5

Supportive Mangement of Diarrhea

Answer 5

• oral rehydration > IV
• rehydration solutions
• clear liquids
• some infectious diarrheas cause lactase deficiency –> avoid milk
• Grade 3-4 diarrhea (fever, neutropenia, dehydration, blood) –> admission
  
  • IV
  • octreotide
  • opioids
  • antidiarrheals

Question 6

Specific Medication management of diarrhea

Answer 6

• cause specific:
• pancreatic enzyme replacement
• cholesytramine (bile acid binding resin) - chologenic diarrhea
• Sulfasalazine –> prevention radiation diarrhea
• methysergide, cyprohepatdine (peripheral serotonin antagonists)– carcinoid
• 5ht3 antagonists –> carcinoid
• Metronidazole –> C diff

Question 7

General treatment of diarrhea : ABSorbent

Answer 7

• Absorbent :
  
  • absorb water to form gelatinous mass with increased stool consistency
  • Pectin
  • Methylcellulose
• ADsorbent:
  
  • take up dissolved substances onto their surfaces (bacteria, toxins, water)
  • Natural minerals
  • Kaolin and attapulgite
• Mucosal Prostaglandin inhibitors
  
  • stop intestinal water and electrolyte secretion
  • Bismuth subsalicylate
  • ASA, mesalazine
• Opioids
  
  • gut opioid receptors
  • reduce peristalsis, increase anal sphincter pressure, reduce electrolyte secretion
  • Loperamide 4mg/day - doesn’t cross BBB, few AE
  • Codeine, morphine etc also options

Question 8

Diarrhea medications ADsorbent

Answer 8

ADsorbent:

• take up dissolved substances onto their surfaces (bacteria, toxins, water)
• Natural minerals
• Kaolin and attapulgite

Question 9

Diarrhea medications : Mucosal prostaglandins

Answer 9

Mucosal Prostaglandin inhibitors

• stop intestinal water and electrolyte secretion
• Bismuth subsalicylate
• ASA, mesalazine

Question 10

Diarrhea Medications : Somatostatin analogues

Answer 10

Somatostatin analogues

• mimic activity of natural gut hormone on epithelial receptors
• inhibitis peristalsis and secretions
• carcinoid, ZE, Verner Morrison sx.
• ileostomy, enterocolic fistula
• Octreotide - secretory diarrhea
• 1500 mg / day

Question 11

Diarrhea medications : Opioids

Answer 11

Opioids

• gut opioid receptors
• reduce peristalsis, increase anal sphincter pressure, reduce electrolyte secretion
• Loperamide 4mg/day - doesn’t cross BBB, few AE
• Codeine, morphine etc also options