Constipation

• Constipation


  A symptom rather than a condition/disease, arises when the patient experiences a reduction in their normal bowl habits accompanied with more difficult, infrequent defecation involving straining and passage of lumpy, hard, uncomfortable stools
• Rome II Criteria for Constipation

  • Two or more of the following for at least 12 weeks out of the last 12 months:
  • Straining at defecation for at least ¼ of the time
  • Lumpy or hard stools for at least ¼ of the time
  • Sensation of ano-rectal obstruction for at least ¼ of the time
  • Sensation of incomplete evacuation for at least ¼ of the time
  • Manual manoeuvres
  • Three or fewer bowel movements a week
• Constipation is very common and occurs in all age groups, increasing with age, especially being common in older adults
• Constipation affects about 2%-27% of general population and women are 2-3 times more likely to suffer from it than men
• Constipation is increased in institutional settings, black patients and in deprived socio-economic groups
• 25% to 40% of all people over the age of 65 have constipation
• 40% of women in late pregnancy experience constipation
• Normal function of the large intestine

  To remove water and various salts from the colon and drying and expelling the faeces
• Cause of constipation


  Decrease in intestinal tract transit time of food due to altered motility, which allows greater water resorption from the large bowl, leading to harder stools that are more difficult to pass
• Causes of constipation


  • Deficiency in dietary fibre
  • Change in lifestyle and/or environment
  • Medication
  • Poor fluid intake
  • Poor bowl habit
  • Travel
  • Pregnancy (hormonal changes slow down gut movements and baby takes up room)
  • Reduced mobility
  • Laxative abuse
  • Underlying conditions, e.g. eating disorders
• Symptoms of constipation


  • Inability to defecate
  • Discomfort on passing stool
  • Abdominal discomfort or cramps
  • Bloating
  • A feeling of incomplete emptying of the rectum
  • A feeling of obstruction or blockage
  • A need to manually assist defaecation
  • Irritability and decreased appetite in children
  • Specks of blood in the toilet (usually due to straining at stool)
• Bright red blood in stool

  Usually due to haemorrhoids or anal fissure, can be managed in the pharmacy
• Substantial blood loss (stools appear tarry, red or black)

  Requires referral
• Questions to ask when assessing constipation

  1. Details of bowel habit

  2. Duration (14 days or more requires referral)

  3. Age (elderly common, child requires referral)

  4. Pain on passing stool (may indicate anal fissure or haemorrhoids)

  5. Presence of blood (bright red suggests haemorrhoids/fissure, tarry/black suggests GI bleed)

  6. Other symptoms (abdominal pain, bloating, nausea/vomiting)

  7. Changes in diet or life events that may have precipitated constipation
• Complications of constipation


  • Haemorrhoids
  • Faecal impaction
  • Faecal and urinary incontinence
  • Rectal bleeding
  • Anal fissure
  • Rectal prolapse
• Reasons for referral


  • Unexplained weight loss
  • Blood in stool
  • Constipation with nausea and vomiting
  • Impacted
  • Suspected laxative abuse
  • Dehydration, electrolyte imbalance
  • Damage to nerves and muscles of gut
  • Patient 40 years with a marked change in bowel habits with no obvious cause (suspect rectal carcinoma)
  • Constipation lasting longer than 14 days with no identifiable cause
  • Tiredness (check for anaemia or thyroid dysfunction)
  • Pain on defecation that might cause the patient to suppress the defecation reflex (check for anal fissure)
• Constipation is rarely caused by serious bowel conditions like bowel cancer
• Symptoms of bowel cancer

  • A persistent change in bowel habit
  • Blood in the stools
  • Abdominal pain, discomfort or bloating always brought on by eating
• Most people with symptoms of bowel cancer do not actually have bowel cancer
• Lifestyle measures for managing constipation

  • Fibre rich foods (30g daily recommended)
  • Adequate fluid (2L/day)
  • Foods containing sorbitol
  • Exercise
  • Proper toileting habits (go when needed, unhurried, regular routine, correct position)
• Laxative types


  • Bulk-forming (first-line after lifestyle advice)
  • Osmotic (second-line)
  • Stimulant
  • Stool softeners (faecal softeners and lubricants)
• Bulk-forming laxatives


  Increase faecal volume like fibre, retain fluid in stool, soften faeces, stimulate peristalsis. Work within 12-36 hours but can take up to 72 hours. Examples: Wheat bran, ispaghula husk, Sterculia, Methylcellulose. Safe in pregnancy and breastfeeding.
• Osmotic laxatives


  Draw water from intestinal wall into gut lumen, raise intra-luminal pressure thus increasing volume of contents stimulating peristalsis. Work within 4-72 hours. Examples: Lactulose, Magnesium sulphate, Macrogols, Glycerol.
• Stimulant laxatives


  Stimulate nerves in large intestine, increase peristalsis & gut motility. Work within 8-12 hours. Examples: Senna, Bisacodyl, Docusate sodium, Sodium picosulfate, Glycerol. Avoid in pregnancy if possible.
• Stool softeners


  Faecal softeners: Anionic surfactants that lower surface tension of intestinal content, allowing fat and fluid to penetrate, emulsify and soften faecal matter. Faecal lubricants: Penetrate and soften faeces, coat surface to facilitate passage.
• Prucalopride


  Selective 5HT4-receptor agonist with prokinetic properties, used for chronic constipation when other laxatives have failed
• Constipation management in children

  • Dietary advice (increase fluid and fibre)
  • Increase activity
  • Use osmotic/stool softeners/stimulant laxatives
• Constipation management in pregnancy/breastfeeding

  • Dietary and lifestyle advice
  • Bulk forming laxatives (e.g. ispaghula)
  • Osmotic laxatives (e.g. lactulose, macrogols)
  • Short course of stimulant laxatives (e.g. senna, bisacodyl)