8.3 (10.3) Constipation and diarrhea

Question 1

List neurotransmitters involved in the regulation of:
- Intestinal motility - list 3 NTs
- Fluid handling - list 3 NTs

Answer 1

Peristalsis
◆ 5-hydroxytriptamine (5-HT)/ serotonin
◆ vasoactive intestinal protein (VIP)
◆ acetylcholine (Ach)

Fluid handling
◆ 5-hydroxytriptamine (5-HT)/ serotonin
◆ vasoactive intestinal protein (VIP)
◆ substance P

◆ neurokinin 1 and 2 receptors

Question 2

List FOUR ways in which opioids cause constipation and TWO opioid receptors involved

Answer 2

bind mu- & kappa- receptors causing:
◆ dec peristalsis
◆ dec gut/rectal distension sensation
◆ dec intestinal secretions
◆ inc fluid reabsorption
◆ inc sphincter tone

Question 3

A patient needs to be started on opioids, but is extremely sensitive to constipation. Which THREE opioids may have reduced constipating effect?

Answer 3

◆ methadone
◆ fentanyl
—
◆ buprenorphine
◆ alfentanil
—
◆ tramadol
◆ tapentadol

Question 4

List FIVE functional factors that can lead to constipation

Answer 4

◆ Diet
- low fibre
- anorexia
- poor food/fluid intake

◆ Environment
- lack of privacy
- need for toileting assistance
- cultural issues

◆ Other
- inactivity
- age
- depression
- sedation

FS: think about non-pharm tx for constipation ( OT, PT, SWK, dietician)

Question 5

List FIVE classes of medications that can cause constipation

Answer 5

◆ Opioids*
◆ Anticholinergic drugs*
◆ Antidepressants (serotonin)
◆ Antiemetics (serotonin)
◆ Iron*
◆ Antacids (Ca & Al compounds)*
◆ Diuretics (drying)*
◆ Anticonvulsants (sedating)
◆ Chemotherapy
◆ Vinca alkaloids (Vincristine)

Table 8.3.1

Question 6

List THREE neurological disorders that can cause constipation

Answer 6

◆ autonomic dysfunction
◆ spinal/cerebral tumor
◆ spinal cord involvement

Table 8.3.1

Question 7

List FIVE structural issues that can cause constipation

Answer 7

◆ Abdo/pelvic mass
◆ diverticular dz
◆ hernia
◆ colitis
◆ radiation fibrosis

◆ rectocele
◆ hemorrhoids
◆ Anal fissure/stenosis
◆ Ant mucosal prolapse

Table 8.3.1

FS: ABCD of BO (adhesion, bulge, cancer, diverticulum) + rectum

Question 8

List FIVE metabolic problems that can cause constipation

Answer 8

◆ Dehydration*
◆ uremia*
◆ hypercalcemia*
◆ hypokalemia*
◆ Diabetes mellitus*
◆ hypothyroidism*

Table 8.3.1

Question 9

An elderly patient has not had a bowel movement in 2 days. Today they have diarrhea and fecal incontinence. What is your provisional diagnosis? What investigation will you do? How will treat this patient?

Answer 9

fecal impaction with overflow incontinence

abdo exam with rectal exam

enema and disimpaction with sedation

then start oral stimulant and osmotic laxative (good evidence for daily PEG in fecal impaction)

Question 10

Name 3 constipation assessment scales

Answer 10

◆ Bristol Stool Form Scale*
◆ Victoria Bowel Performance Scale (BPS)*
◆ Numerical rating of constipation on Pall assessment scales
◆ Stool Symptom Screener (SSS)*

◆ Bowel Function Index (BFI)
◆ Constipation Assessment Scale(CAS)
◆ Pt Assessment of Constipation-Symptoms (PAC-SYM)

Question 11

List FIVE non-pharm mgmt for constipation

Answer 11

◆ Has evidence:
- abdominal massage
- position: forward posture + footstool

◆ Practical:
- Dietician - fluid/fibre intake balance
- PT - gentle movement (even bed to chair)
- OT - assisted walking, attention to privacy

Question 12

You are designing a bowel protocol for hospice. List SIX medications you would include in your protocol

Answer 12

sennosides (stimulant laxative)
polyethylene glycol 3350 (macrogol) - renders water unabsorbable by the gut)
Laculose (osmotic laxative - increases secretion of water into gut lumen)
bisacodyl supp (stimulant supp)
glycerin supp (lubricating supp)
sodium phosphate enema
Mineral oil enema?

?sodium picosulfate oral (well tolerated stimulant laxative)

Question 13

List THREE reasons bulk forming agents are not helping in cancer patients

Answer 13

◆ need to be taken with at least 200–300 mL of water

◆ consistency is unacceptable to many people who feel unwell

◆ effectiveness in severe constipation is doubtful

Question 14

List THREE rectal interventions for management of constipation

Answer 14

◆ suppositories
◆ enemas
◆ manual evacuation/digital fragmentation of stool, w/ appropriate analgesia and sedation

Question 15

What is the role of methylnaltrexone? How does it work?

Answer 15

◆ Methylnaltrexone is a peripherally acting mu-opioid receptor antagonists (PAMORAs).
- antagonizes only peripherally located opioid receptors while sparing centrally mediated analgesic effects of opioid pain medications.

◆ For OIC which has not responded to conventional laxative therapies

Relistor

Question 16

What is the most common cause of diarrhea in the setting of palliative care? How would you manage this?

Answer 16

imbalance of laxative therapy

Temporarily stop laxatives for 24-48h and then reinstate at lower dose

Question 17

List FIVE classes of medication that can cause diarrhea

Answer 17

◆ Antibiotics
◆ Laxatives
◆ Chemotherapy
◆ Immunotherapy
◆ Tyrosine kinase inhibitors
◆ NSAID, notably diclofenac

Question 18

List FOUR “other” causes of diarrhea

Answer 18

◆ Diet
- excess fibre
- fruit
- alcohol
- spices
- sorbitol

◆ Other
- radiation colitis
- graft vs host dz

new

Question 19

List THREE physiological (anatomical/structural) causes of diarrhea

Answer 19

◆ Cancer
- rectal/colonic
- pancreatic
- carcinoid

◆ Obstruction (overflow)
- malig bowel obstruction
- fecal impaction

◆ Malabsorption
- pancreatic carcinoma
- colectomy
- gastrectomy
- ileal resection

FS: IIEAT (expanding on ANATOMY - COM)

Question 20

List SIX concurrent diseases that can cause diarrhea

Answer 20

◆ Diabetes mellitus
◆ Hyperthyroidism

◆ Chron’s Dz
◆ Ulcerative Colitis
◆ Diverticulitis

◆ Gastrointestinal infection
◆ Irritable bowel syndrome

Question 21

What is the relationship between length of bowel removed in an ileal resection and subsequent risk of diarrhea? If diarrhea develops what is it caused by?

Answer 21

Ileal resection reduces the gut’s ability to reabsorb bile acids (97% are normally recirculated) -> producing chologenic diarrhoea (watery and explosive)

• <100 cm of terminal ileum is removed, fat malabsorption generally does not occur — as the liver can compensate for the increased biliary loss (by producing more bile acids)
• > 100 cm results in relative bile acid deficiency and hence fat malabsorption -> diarrhoea

-Also produces a disaccharidase deficiency proportional to the length of removed -> osmotic diarrhoea due to carbohydrate malabsorption

FS: bile acid increase peristalsis + gut fluid secretion –> diarrhea

Question 22

A patient has a total colectomy and develops a high output ileostomy. What four diet replacements will the pt require?

Answer 22

-average of an extra litre of water per day
-7 g of extra salt to compensate
-Iron
-vitamin supplementation (A, D, E, K (fat soluble) and B and C)

Question 23

List four red flag features in a patient with diarrhea

Answer 23

◆ fever
◆ neutropenia
◆ blood in stool
◆ dehydration

Question 24

A patient has a stool anion gap of 25 (secretory diarrhea), what type of tumor may be responsible for this?

Answer 24

Anion gap = the difference between the stool osmolality and double the sum of the cation concentrations

> over 50 mmol/L = osmotic diarrhoea
<50 mmol/L = secretory diarrhoea, resulting from active secretion of fluid and electrolytes, as in the WDHA syndrome.

The WDHA syndrome (watery diarrhoea hypokalaemia achlorhydria) is associated with tumours of the pancreatic islet cells and of the sympathetic nervous system, including the adrenal glands, and can occur with bronchogenic carcinomas. VIP is thought to be the causative hormone

Ileal resection gives rise to a mixed picture, which will become purely secretory if the patient can be fasted

FS: VIPoma - type of neuroendocrine tumor

Question 25

Diarrhea from what TWO etiologies is likely to require aggressive IV fluid rehydration due to volume loss?

Answer 25

infection (Clostridium difficile, Salmonella, Escherischia coli, and Campylobacter)

neutropenia enterocolitis

Question 26

List specific treatments for each of the following types of diarrhea:
pancreatic insufficency
chlorogenic diarrhea
XRT induced diarrhea
carcinoid syndrome
c diff infection

Answer 26

pancreatic insufficency - pancrealipase

chologenic diarrhea - cholestyramine

XRT induced diarrhea - cholestryamine, ASA, sulfasalazine (prophylaxis),

carcinoid syndrome - methysergide, cyproheptadine

c diff infection - metronidazole, vancomycin

Question 27

A patient is admitted to the hospital for a procedure that is schedule the next day. No medication changes are made. The patient develops infectious bloody diarrhea. What organism may be responsible for this? The patient requests an antidiarrheal medication. What do you tell them?

Answer 27

c difficile colitis, salmonella, e coli, campylobacter

no - risk of toxic megacolon

Question 28

A 27 year old man with AIDS presents with diffuse watery diarrhea. Aside from fluid resuscitation and initiation of abx, what agent may be effective for severe diarrhea?

Answer 28

octreotide - useful in secretory diarrhea

Question 29

A patient present with NV alternating diarrhea and constipation and colic. What might this represent and list two risk factors

Answer 29

Intestinal obstruction (partial)

Risk factors - intra-abdo malignant deposits, previous abdo sx

FS: ABCD (adhesion, bulge, cancer, diverticulum)

Question 30

What are THREE side effects of peripherally acting mu-opioid receptor antagonist (PAMORAs)?

Answer 30

◆ stomach pain, gas, bloating
◆ mild nausea or diarrhea

◆ anxiety
◆ runny nose
◆ chills, sweating, or hot flashes

◆ headache, dizziness
◆ muscle spasms, tremors

FS: opioid withdrawal symptoms

Question 31

Current definition of constipation (ROME III criteria)?

Answer 31

Presence of any 2 symptoms for at least 12 weeks in the 12 months preceding assessment:

• Fewer than 3 BMs/week
• Lumpy or hard stool
• Straining during bowel movements
• Sensation of incomplete evacuation, blockage, or obstruction
• necessity for a manual evacuation to remove stool from the rectum.

new

Question 32

Name SEVEN key questions in the assessment of constipation.

Answer 32

◆ Time of day (AM/PM/irregular)?
◆ Recent changes in bowel patterns (pain, cramping, offensive smell, more/less often)?

◆ Frequency of bowel movements
◆ Size and consistency of the stool (hard, small, ‘pebble-like’ , soft, watery)?
◆ Sensation of evacuation (complete or incomplete)?
◆ Need for digital manipulation to assist evacuation?

◆ Evidence of halitosis, nausea, vomiting, flatus, or urinary incontinence?
◆ Urge to defecate (presence or absence)?
◆ Evidence of faecal impaction (loose watery stool
bypassing a solid faecal mass)?
◆ Faecal incontinence (presence or absence, including rectal leakage)?
◆ Evidence of blood or mucus or pain on defecation?
◆ Risk of abdominal adhesions or intestinal obstruction?
◆ Current and previous laxative use (including ‘over-the counter’ meds)?

Box 8.3.1

FS:
- OPQRST
- ROME III criteria (frequency, consist, strain, incomplete, DRE over 12 weeks)
- DDX: structural (ABCD + rectal), meds, environmental/functional (diet/OT/PT)

Question 33

Physical exam to assess presence/absence of constipation.

Answer 33

◆ Abdo exam + auscultation
- distention
- masses
- liver enlargement
- tenderness
- inc/dec bowel sounds
◆ Perineal inspection
- skin tags
- anal warts
- prolapse
- fissures
- perianal ulceration
◆ DRE
- inner hemorrhoids
- sphincter tone
- tenderness (WP: always tender?)
- obstruction/stenosis
- presence/absence stool
- masses

Table 8.3.2

Question 34

Name TWO laxative types. Name ONE of each type.

Answer 34

◆ Osmotic laxatives
- hold water in the gut lumen -> reduce desiccation
Ex: Lactulose, Mag hydroxide aka milk of magnesia, Macrogols (PEG)

◆ Stimulant laxatives
- hydrolysed by colonic bacteria with both motor and sensory effects
Ex: anthranoid plant cmpds = senna

◆ Bulk laxatives
- limited value
Ex: methyl cellulose, ispaghula, psyllium

Question 35

Name FOUR key questions in the history of diarrhea?

Answer 35

◆ Frequency of defecation
◆ Description and nature of stool, consistency, offensive smell, and presence of blood or mucus
◆ Current medication and any changes made to regimen prior to diarrhoea
◆ A clear history of laxative therapy and adherence or change to the regimen
◆ Any recent clinical intervention such as chemotherapy or radiotherapy.

FS:
OPQRST
Frequency, consistency, volume
DDX: IIEAT (infection, inflammation, endo, anatomy - overflow, tx)

Question 36

Name FOUR catagories of anti-diarrhea agents.

Answer 36

◆ Absorbent agents
- offer a thicker consistency to the stool and so create bulk by absorbing water.
Ex. Methylcellulose (fiber), pectin.

◆ Adsorbent agents
- ‘clay surfaces’ take up water or bacteria to their surfaces.
Ex. kaolinite (Kaolin)

◆ Mucosal prostaglandin
- inhibitors inhibit intestinal water and electrolyte secretion
Ex. bismuth and aspirin

◆ Opioids
- if you know, you know!
Ex. loperamide, eluxadoline

◆ somatostatin analogues
- mimic activity of the natural gut hormone inhibiting secretion and peristalsis
Ex. octreotide

◆ anticholinergic
Ex lomotil