Constipation

Question 1

Constipation - etiology:

Answer 1

• prolonged immobilization
• Drugs (opioids, anticholinergic such as TCA, octerotide, antacids, 5HT3 antagonists antiemetics)
• Opioid related constipation is R mediated via both central & peripheral mechanisms. Causing extended GI transit time and dry up the intraluminal content.
• Hypomobility of the gut (in elderly/2nd to DM)
• Decreased fluid and food intake.
• Metabolic causes (hypercalcemia, hypokalemia)
• Neurological deficits (spinal cord/ nerve root lesions)
• Local (anal tissue)
• Psychological (use of bed pan/ commode / briefs)

Question 2

Complications of constipations:

Answer 2

• abdominal bloating, pain, discomfort
• overflow diarrhoea
• fecal incontinence
• urinary retention / frequency
• ‘obstipation’ - partial / complete BO from severe constipation.
• not supported by literature: delirium in frail pts.

Question 3

Constipation score

Answer 3

looking at the 4 quadrants of the abdomen (corresponding to the different parts of the large colon)
assess the amount of stool in each:
0 - no stool
1- less the 50% of the lumen is with stool
2 - more than 50% of the lumen has stool
3- stool completely occupy the lumen of the colon
score greater than 7 indicates significant constipation that requires treatment

Question 4

Prevention of constipation:

Answer 4

goal is to achieve BM every at least every 3rd day.
maintain regular laxative regime with either:
- bowel stimulant (e.g Senna - 1-2 tabs PO OD, can titrate up to TID)
- osmotic laxative (e.g Lactulose 15-30 ml PO OD, can titrate up to 60 ml daily/ PEG 17 gram can go up to QID or less to q2-3 days)
lactulose can cause cramping and is very sweet. PEG is tasteless.
- for pt who cannot swallow - regular suppository (bisacodyl) or fleet enema (q3-4 days)

Question 5

Management of established constipation:

Answer 5

usually goal would be to clear the constipation and start a regular preventive regime:

• fleet enema / bisacodyl supp followed by another dose, 12-24 hr later if first did not work. if still unsuccessful, consider an oil retention enema followed by water enema.
• in severe cases, where considerable fecal mass is suspected in the proximal bowel, consider oral magnesium citrate (150-250 ml), drunk slowly over several hours