Constipation management in the community

Constipation & Causes

Constipation is when an individual experiences a reduction in normal bowel habits, with more difficult defeacation and dryer/harder stools. Constipation is quite common. Around two times more common in women as in men, it affects all age groups but is more prevalent in the elderly.

Constipation is commonly caused by increased transit time of food through the gastrointestinal tract. More water is absorbed from the bowel back into the bloodstream, meaning stools are drier and harder to pass (Rutter, 2017).

Various other factors contribute to constipation including:

• Social – Diet with little fibre or having low fluid intake
• Psychological – Ignoring the need to defecate or Avoidance due to previous pain associated to defecation
• Physical – a sedentary lifestyle, pregnancy and old age.
• Medication – some drugs can have constipation as a side effect, i.e. codeine.

Clinical Features

In addition to the difficulty passing stools, patients may also feel bloated, suffer from abdominal discomfort and there may be specks of bright red blood in stool due to straining. Red flags associated with constipation require referral to a doctor and consist of the following:

• Black, tarry stools
• Patient over 40 with a sudden change of bowel movement, with no clear cause
• Constipated for over 14 days, no clear cause identified
• Associated feeling of tiredness (Rutter, 2017)

Differential diagnosis (questions to ask the patient)

1. How long have the symptoms been going on for?
   • Child with symptoms for more than 7 days, or an adult with symptoms lasting more than 14 days should be referred.
2. Has the patient recently changed their diet?
   • Yes = This is a factor for constipation, establish changes in diet and assess
   • No = ask further questions
3. Is the patient on any medication that commonly causes constipation?
   • Yes = Speak with GP and provide appropriate treatment
   • No = Refer to the GP, if no cause can be clearly identified
4. Did the patient have a sudden change in bowel habits or a rectal bleed?
   • Yes = Refer to eliminate sinister pathology such as carcinoma
   • No = Ask further questions
5. Is there pain on defecation?
   • Yes = Could be due to an anal fissure or haemorrhoid, assess and provide treatment
   • No = ask further questions
6. Does the patient have alternating bouts of diarrhoea?
   • Yes = This could be IBS, refer for further investigation
   • No = ask further questions

Treatment

Bulk-forming Laxatives (Ispaghula husk, Methylcellulose and Sterculia – Granules and powder)

• Mechanism: These laxatives increase the water content in stools and lubricates the intestine. Lubrication helps the transit of stools in the intestine and increased water content increases the bulk of the stool and makes it softer, this increases tension in the bowel triggering peristalsis (EMA, 2014).
• Indication: Laxative for treating constipation.
• Side-effects: Flatulence, abdominal discomfort, and bloating are common. In rare cases, the patient can experience abdominal distension, bronchospasm, difficulty swallowing.
• Counselling:
  • Take with water, preferably after meals.
  • Patients should be advised that full effect may take up to a few days to be seen (NICE, 2020).
• Evidence: Systematic reviews and clinical evaluations support the use of bulk-forming laxatives. Most have mainly looked at Ispaghula husk, in a multi-centre study, it was found to be an effective treatment for constipation and had lower occurrence of adverse events compared to other laxatives (Dettmar, 1998).

Stimulant Laxatives (Senna, Glycerol, Sodium Picosulphate and bisacodyl)

• Mechanism: Act on the intestine wall, stimulates the nerve endings in the gut causing muscle contractions, this leads to peristalsis which helps transit of stool. They also reduce the absorption of water from the lumen of the bowel (Bashir, 2020).
• Indication: Laxative for treating constipation.
• Side-effects: Abdominal discomfort/pain, nausea, vomiting and diarrhoea (BMJ, 2020).
• Counselling:
  • Take at night for bowel movement in the morning
  • Avoid long-term use as it can lead to a lazy bowel.
  • Avoid during pregnancy.
• Evidence: A double blind RCT which looked at the effectiveness of stimulant laxatives – sodium Picosulphate and bisacodyl, showed that they significantly improved symptoms of constipation in comparison to placebo. Sodium Picosulphate was also shown to be well tolerated and improves quality of life (Stefan Mueller-Lissner, 2010).

 Osmotic Laxatives (Lactulose, Macrogols and magnesium salts)

• Mechanism: Makes the solution of the gut more solute concentrated, causing water to move from the blood stream into the bowel, this softens stool and increases its volume, making it easier to pass (NICE, 2020).
• Indication: Laxative for treating constipation.
• Side-effects: Bloating, diarrhoea, flatulence, nausea, vomiting and in rare occasions hypernatremia (BMJ, 2020).
• Counselling:
  • Effects can take up to 3 days to be seen.
  • Inform your doctor or pharmacist if there is no improvement of symptoms after several days (NICE, 2020).
• Evidence:  A multi-centre RCT looking at the treatment of chronic constipation found that the osmotic laxative, polyethylene glycol, was safe and effective in long term use. Adverse events were not statistically significant (Dipalma, 2007).

Stool Softeners (docusate)

• Mechanism: It has a surfactant effect, it allows fat and water to penetrate feces in the intestine, which softens the stool, making it easier to pass (DrugBank, 2021).
• Indication: Laxative for treating constipation  (Rutter, 2017).
• Side-effects:  In rare cases, abdominal cramps, nausea, rash (NICE, 2021).
• Counselling:
  • Caution advised for use during breastfeeding, as it is present in milk following oral administration.
  • Liquid oral administration takes up to 2 days to work but rectal route acts with 20 minutes.
  • Do not take for more than 1 week (NHS, 2021).
• Evidence: Stool softeners such as docusate sodium is commonly used for constipation however there isn’t much clinical evidence to support its use. It’s effectiveness is on an individual basis. (Yoko Tarumi, 2013)

 Self-care advice for patients:

• Have a healthy-balanced diet and have regular meals. Increase fibre intake gradually, and have enough fruits, vegetables, and whole grains.
• Increase fluid intake to avoid dehydration.
• Increase activity levels and exercise more.
• Have a regular toilet routine.

References

Bashir, A. (2020, 09). Laxatives. Retrieved from Ncbi.nlm.nih.qov: https://www.ncbi.nlm.nih.gov/books/NBK537246/

BMJ. (2020, 9 10). Constipation | Treatment algorithm. Retrieved from Best Medical Practice: https://bestpractice.bmj.com/topics/en-gb/154/treatment-algorithm

Dettmar, P. W. (1998). A multi-centre, general practice comparison of ispaghula husk with lactulose and other laxatives in the treatment of simple constipation. Current medical research and opinion, 227-233.

Dipalma, J. A. (2007). A randomized, multicenter, placebo-controlled trial of polyethylene glycol laxative for chronic treatment of chronic constipation. The American journal of gastroenterology,, 1436-1441.

DrugBank. (2021). Docusate: Uses, Interactions, Mechanism of Action | DrugBank Online. Retrieved from Go.drugbank.com: https://go.drugbank.com/drugs/DB11089

EMA. (2014, 06). Plantaginis ovatae seminis tegumentum - European Medicines Agency. Retrieved from European Medicines Agency: https://www.ema.europa.eu/en/medicines/herbal/plantaginis-ovatae-seminis-tegumentum

NHS. (2021). Docusate: a laxative to treat constipation. Retrieved from nhs.uk: https://www.nhs.uk/medicines/docusate/

NICE. (2020, 11). Choice of laxatives | Prescribing information | Constipation | CKS | NICE. Retrieved from Cks.nice.org.uk: https://cks.nice.org.uk/topics/constipation/prescribing-information/choice-of-laxatives/

NICE. (2020, 11). Factors affecting choice of laxative | Prescribing information | Constipation | CKS | NICE. Retrieved from Cks.nice.org.uk: https://cks.nice.org.uk/topics/constipation/prescribing-information/factors-affecting-choice-of-laxative/

NICE. (2021). DOCUSATE SODIUM | Drug | BNF content published by NICE. Retrieved from BNF: https://bnf.nice.org.uk/drug/docusate-sodium.html

Rutter, P. (2017). Gastroenterology. In P. Rutter, Community Pharmacy: Symptoms, Diagnosis and Treatment (pp. 179-187). Elsevier.

Stefan Mueller-Lissner, M. A. (2010). Multicenter, 4-Week, Double-Blind, Randomized, Placebo-Controlled Trial of Sodium Picosulfate in Patients With Chronic Constipation. American Journal of Gastroenterology, 897-903.

Yoko Tarumi, M. P. (2013). Randomized, Double-Blind, Placebo-Controlled trial of oral docusate in the management of constipation in hospice patients. Journal of Pain and Symptom Management.