Spot light on constipation
Last time we spoke about the state of our poo (or stool) and what it can tell us about our health and wellbeing. This week we’ll discuss a common problem that affects everyone occasionally. Read on for a discussion about constipation …
What is constipation?
Constipation refers to infrequent bowel movements that are difficult to pass. The stools or faeces may be hard, dry, uncomfortable, difficult and/or be painful to pass. There may also be a need to strain when passing stools or a feeling of incomplete evacuation. Medically, constipation generally describes infrequent defecation (usually <3 times/week) coupled with changes to the stools as described above (note: medical guidelines state that constipation should not be defined or diagnosed by stool frequency alone).
How do stools become hard and dry?
Food leaves the stomach as partly digested material. When transiting the colon (large intestine) valuable fluid is removed and stools of a normal consistency are formed. The longer faeces stay in the colon, the drier and harder they get because more fluid ends up being removed. If we delay going to the toilet, the amount of faecal material increases leading to formation of a large hard stool which can be painful and difficult to pass. Often times the expectation of discomfort makes people reluctant to go to the toilet, creating a vicious cycle.
Are there different types of constipation?
Constipation can be acute or chronic (long standing). Acute constipation refers to constipation that starts suddenly and usually lasts for a few days. Chronic constipation refers to infrequent bowel movements or hard to pass stools, persisting for several weeks or longer.
Are there risk factors for constipation?
Additional factors may contribute to constipation in older people, particularly residents of aged care facilities factors (eg lack of privacy, hard access to toilet facilities). Prolonged constipation may lead to faecal impaction, which may lead to urinary or faecal overflow incontinence. Constipation occurs frequently in people with dementia and depression.
What causes constipation?
Constipation usually arises when stools move too slowly through the digestive tract or cannot be eliminated effectively from the rectum (becoming hard and dry). Constipation can be caused by a number of factors, ranging from simple dietary or lifestyle factors to more specific conditions which may require medical or surgical management.
Common causes of constipation include not eating enough foods high in fibre, not drinking enough fluids (dehydration), having poor bowel habits (eg ignoring the urge to defecate), undertaking inadequate physical activity (eg from decreased mobility) and/or experiencing a change in environment (eg holiday, entry into residential aged care). Use of certain medications can also lead to constipation.
Chronic constipation has many possible causes including:
- Blockages in the colon or rectum which may slow or stop movement of stool (eg anal fissure, bowel obstruction, colon cancer, narrowing of the colon, abdominal cancer that presses on the colon, rectal cancer, rectal bulge through the back wall of the vagina (rectocele)
- Neurological problems affecting nerves supplying the colon and rectum which normally cause muscles to contract and move stool through the intestines (eg autonomic neuropathy, multiple sclerosis, Parkinson’s disease, a spinal cord injury, stroke)
- Problems with pelvic muscles involved in having a bowel movement (pelvic floor muscles) (eg inability to relax the pelvic muscles to allow for a bowel movement (anismus); pelvic muscles don’t coordinate relaxation and contraction correctly (dyssynergia), weakened pelvic muscles (from surgery, child birth)
- Conditions affecting hormones required for fluid balance (eg diabetes, overactive parathyroid gland (hyperparathyroidism), underactive thyroid (hypothyroidism), pregnancy
Which medications cause constipation?
Some medications can cause constipation as a side effect of their use. Sometimes regular bowel function can be restored by switching to alternative medication(s).
Over the counter medications that can may cause constipation include aluminium-and calcium-containing antacids; oral calcium supplements (used in bone loss conditions such as osteoporosis) and oral iron supplements (used in iron deficiency/anaemia).
Examples of prescription medications that can may cause constipation include:
- Opioids (used for pain management, most often in cancer & end of life care)
- Drugs with anticholinergic effects (selected drugs with specific actions eg oxybutynin (overactive bladder and incontinence), benzhexol (Parkinson’s disease), tricyclic antidepressants; clozapine, olanzapine, risperidone, quetiapine (antipsychotics))
- 5-HT3 – receptor antagonists (prevention and treatment of nausea and vomiting, particularly when caused by chemotherapy, radiation therapy, or postoperatively eg ondansetron)
- Verapamil (used to lower blood pressure & other uses)
What are the complications of constipation?
Constipation rarely causes complications or long-term health problems, especially when treated. Occasional constipation is very common and doesn’t cause too many problems. Chronic constipation, on the other hand, is more likely to interfere with peoples’ daily activities and to increase their risk of experiencing possible complications.
Complications associated with chronic constipation include:
- Rectal bleeding caused by straining to pass stools
- Haemorrhoids (swollen veins in and around the anus) caused in response to straining to pass a bowel movement
- Anal fissures (torn skin in the anus) caused by passing of large or hard stool which causes tiny tears in anal tissue
- Faecal impaction (stool cannot be expelled) because hard stool has accumulated and gotten stuck in the intestines; problems associated with faecal impaction include swelling of the rectum, loss of sensation in and around the anus, bowel incontinence, bleeding from the anus, rectal prolapse (see below)
- Rectal prolapse (intestine protrudes from the anus) caused by repeated straining to have a bowel movement which can lead to stretching of a small section of the rectum which protrudes or hangs out from the anus
When should you see a doctor for constipation?
Seeking medical advice about problematic and/or long-standing constipation is important to ensure that there are no serious underlying problems. Discussing any bowel concerns you have with a doctor is important as some causes of constipation are potentially correctable or manageable. As discussed in the last week’s blog, medical advice should always be sought if you have red or black stools that are not related to the foods you have been eating.
Any final words?
If you have any concerns about your health and wellbeing after reading this article, we suggest you make an appointment to speak with GP as soon as possible.
Further Reading
Blog post – Dietary fibre
Blog post – All about pooh
The Better Health Channel (Victorian Government website) has several good articles on constipation:
General article
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/constipation
Constipation in children
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/constipation-and-children
Slow transit constipation
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/slow-transit-constipation
Constipation in Parkinson’s disease
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/parkinsons-disease-and-constipation?viewAsPdf=true