Functional Constipation

This care pathway can be used to guide primary care providers in the management of patients with functional constipation. This care pathway was developed by the specialists at GI Motility Clinic at the Toronto Western Hospital and follows the Rome IV criteria for functional constipation.

SUMMARY OF FUNCTIONAL CONSTIPATION

Functional constipation (FC) (also known as chronic idiopathic constipation) is a disorder of the gut-brain interaction (DGBI) in which the main symptoms are difficult, infrequent, or incomplete defecation. Patients with FC may experience some abdominal pain and/or bloating, but these are not predominant symptoms such as seen in patients with irritable bowel syndrome.

Patients with chronic constipation symptoms without any evidence of structural or metabolic abnormalities are considered to have FC. It is divided into 3 categories: normal-transit constipation, slow-transit constipation, and defecatory or rectal evacuation disorders (uncoordinated rectal propulsion and/or anal sphincter relaxation). Some patients with FC may have overlap between slow-transit constipation and dyssynergic defecation (DD).

Some risk factors include female sex, reduced caloric intake, and increasing age.

Mechanical obstruction, medications, and systemic illness can be secondary causes of constipation and should be excluded. The diagnosis of FC can be made based on clinical history, physical examination, and minimal investigations. The Bristol Stool Form Scale is a useful tool to assess stool form.

ROME IV DIAGNOSTIC CRITERIA

FUNCTIONAL CONSTIPATION

Must include 2 or more of the following:

Straining during more than 25% of defecations
Lumpy or hard stools (Bristol type 1 – 2) more than 25% of defecations
Sensation of incomplete evacuation more than 25% of defecations
Sensation of anorectal obstruction/blockage more than 25% of defecations
Manual maneuvers to facilitate more than 25% of defecations (e.g. digital evacuation, support of pelvic floor)
Fewer than 2 spontaneous bowel movements per week
Loose stools are rarely present without the use of laxatives
Insufficient criteria for irritable bowel syndrome

Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

PRIMARY CARE CHECKLIST

Detailed constipation history and physical assessment
Absence of alarm features:
- Anemia, iron deficiency, GI bleeding
- sudden or progressive changes in bowel habits
- acute or unintentional weight loss
- new onset after the age of 50
- positive family history of colorectal cancer
- FIT positive if done for screening purposes
- abnormality on physical exam
Secondary causes for constipation ruled out (e.g. medication, obstruction, and systemic illness)
The patient meets Rome IV diagnostic criteria for functional constipation
Complete baseline laboratory tests (CBC, TSH, calcium)

ALGORITHM FOR FUNCTIONAL CONSTIPATION

Suspect Functional Constipation (FC)

Consider referral to GI

YES

Alarm Features?

NO

Identify secondary causes for constipation. Complete baseline investigations

Normal investigations

Cause identified

Establish diagnosis for FC.
Meet Rome IV criteria for FC

GENERAL PRINCIPLES OF FC

provide reassurance & manage expectations
review the broad range of stool form & frequency
adequate daily intake of fiber and water
regular exercise
stress reductions
schedule regular toilet routine

Manage secondary causes for constipation

Constipation persists

CONSTIPATION SUBTYPES

*IBS constipation subtype excluded. Refer to IBS section

SLOW TRANSIT CONSTIPATION

Trial of laxatives for 4 to 8 weeks. Reassess maintenance or if the patient needs to step-up therapy:

Psyllium
PEG-3350
Secretagogues (linaclotide, plecanatide)
Prokinetics (prucalopride)

Rescue Therapies:

Glycerin suppositories
Stimulant laxatives (senna, bisacodyl)
Enema

No response

Consider referral to GI for anorectal manometry and balloon expulsion test.

Dyssynergic Defecation

Digital rectal examination

Positive DD

Refer for pelvic floor physiotherapy

Incomplete response

Negative DD

Consider referral to GI for anorectal manometry and balloon expulsion test.

EXPLANATION OF ALGORITHM FOR FUNCTIONAL CONSTIPATION

PHYSICAL & HISTORY ASSESSMENT

When diagnosing FC, a full history and thorough abdominal and anorectal examination are required. There should be limited use of diagnostic tests. It is a diagnosis based on clinical symptoms. Exclude alarm features as listed above. The presence of alarm features should prompt consideration of a referral to a specialist.

It is important to understand the patient’s interpretation of constipation. A detailed history should include:

Onset and duration of symptoms. Constipation over a long period that is not responsive to conservative measures suggests functional constipation. New or abrupt onset of constipation symptoms may indicate a structural disease.
Frequency of bowel movements. The patient should be encouraged to keep a Stool Diary (Appendix 1) over 14 days to track their stool patterns
Associated symptoms (abdominal pain, bloating, or distention)
Assessment of stool consistency, size, and degree of straining during defecation
A history of laxative and herbal medication use and the patient’s response to treatments

Identify secondary causes:

Past medical and surgical history: Obstetrical and surgical histories are particularly important. Some neurological, metabolic or systemic conditions may also explain some cases of constipation
Current medication list: include all prescribed, over-the-counter, and natural/herbal products
Dietary history: review the amount of daily fibre and fluid intake

INVESTIGATIONS

A CBC should be ordered for all patients presenting with constipation to rule out anemia that may require further investigation. Glucose, TSH, and calcium may also be considered if clinically indicated.

GENERAL PRINCIPLES OF FUNCTIONAL CONSTIPATION

Provide reassurance and counsel the patient about the broad range of stool form and frequency. Remind patients that “normal” stool patterns can vary between individuals. The average stool frequency can range from 3 times a day to 3 times a week in the general population. It may be helpful to review the gut-brain axis to help the patient understand their condition and establish realistic treatment goals. The patient should trial a regimen for 4 to 8 weeks and then follow up to reassess their response.

CONSTIPATION SUBTYPES

The patient’s history can be useful in determining the constipation subtype. Although it is not diagnostic, these questions can be helpful to guide the clinician’s assessment.

Hover the cursor over the images for a description of the types of constipation.

Slow Transit

Constipation

Bristol stool forms 1 to 2
Infrequent bowel movements
Laxative dependence
Inadequate caloric intake

Dyssynergic Defecation

Urge to defecate and strain >5 minutes
Sense of incomplete evacuation
Difficulty passing soft stools/suboptimal response to laxatives or fibre
Need for perineal or vaginal pressure to allow passage of stools
Digital manipulation

If dyssynergic defecation (DD) is suspected, the combination of a detailed history and digital rectal examination has shown to be accurate in diagnosing the condition. Patients with DD typically report prolonged straining for more than 5 minutes with a sense of urgency and a sense of incomplete evacuation. Patients with DD often have a suboptimal response to fibre supplementation or laxatives. Treatment involves pelvic floor physiotherapy. An anorectal manometry (ARM) and balloon expulsion test (BET) are not required for a referral for pelvic physiotherapy for those with a suggestive history and physical exam.

If pelvic floor physiotherapy is ineffective, a referral to a specialist for an ARM/BET should be considered.

TREATMENT FOR FUNCTIONAL CONSTIPATION

Initial treatment for FC should start with non-pharmacological interventions. If these interventions fail, pharmacological agents may be considered. Osmotic laxatives may be considered if fibre supplementation is not effective. These medications should be adjusted until there are soft stools. If there is an incomplete response to osmotic laxatives, secretagogues (linaclotide, plencanatide) or prokinetics (prucalopride) should be considered. Stimulant laxatives should be reserved as rescue therapy.

DIETARY FIBER

Insoluble and soluble fibres have been shown to help relieve constipation. Soluble fibre, in particular, has good evidence for the management of constipation. Fibre can cause abdominal distention, bloating, flatulence, and poor taste. Patients should be advised to gradually increase fibre intake to minimize side effects and ensure adherence.

Generally, women need 25 grams of fibre per day and men need 38 grams of fibre per day. On average, Canadians only consume half or less than the recommended amount.

Source: https://www.canada.ca/en/health-canada/services/nutrients/fibre.html

Insoluble fibres are primarily found in fruits and vegetables, legumes, nuts and seeds. These fibres increase stool bulk and stimulate the movement of material through the gut. Soluble fibres increase stool bulk and draw water into the colon. While taking a soluble fibre, patients should be advised to titrate water intake to improve stool form and frequency. If stools are hard, increase water intake. If the patient develops diarrhea, decrease the amount of fibre or water intake. Sources of soluble fibres include psyllium (Metamucil®), guar gum (The Right Fibre4®), inulin (Benefibre®), and oatmeal.

Prunes and kiwis are also effective in alleviating constipation. Eating about 5 to 6 prunes or two kiwis a day has shown to be beneficial.

WATER INTAKE

Adequate water intake can enhance the effectiveness of fibre. Patients should be encouraged to drink 1.5 litres to 2 litres a day if possible.

PHYSICAL ACTIVITY

Exercise has been shown to increase gut transit time and help alleviate constipation symptoms. Discuss with the patient the potential gut benefits of exercise and the overall health benefits. If appropriate, patients should aim for 2.5 hours of moderate to vigorous aerobic activities per week.

Source: https://www.canada.ca/en/public-health/services/publications/healthy-living/physical-activity-tips-adults-18-64-years.html

TOILETING ROUTINE & POSTURE

Patients with infrequent bowel movements should be encouraged to develop a regular toilet routine and not ignore the urge to defecate. For example, the patient may want to wake up earlier and set aside some time to use the toilet after breakfast.

Patients who spend an excessive amount of time on the toilet and have ineffective bowel movements should be encouraged to develop a schedule decreasing the amount of time they spend in the bathroom and only using the toilet for effective bowel movements.

Counsel the patient about the benefits of a proper posture for defecation. Recommend placing a footstool at the toilet’s base to elevate the knees above the hips. This helps to relax the puborectalis muscle to promote stool evacuation.

The I-L-U abdominal massage has also been shown to help move stool contents in the gut. The massages should be done while sitting upright. Instruct the patient to do ten massages for each letter, 2 to 3 times a day or as needed. There are many instructional videos on YouTube if needed.

"I" Massage

Start in the left upper quadrant under the left rib. Using circular motions, massage down toward the left hip bone

"L" Massage

Start in the right upper quadrant under the right rib. Using circular motions, massage across the abdomen toward the left upper quadrant and then down to the left hip bone.

"U" Massage

Start in the right lower quadrant, near the right hip bone. Using circular motions, massage up the right side of the abdomen to the right rib cage.

Then massage across the top abdominal area to the left upper quadrant, then down to the left hip bone.

PHARMACOLOGICAL THERAPY

Medication	Recommended Dose	Side Effects	Patient Education

If there is incomplete response after 4 to 8 weeks, step-up therapy to newer agents.
Linaclotide may be used alone or in combination with prucalopride. Titrate dosing to the desired effect.

Medication	Recommended Dose	Side Effects	Patient Education

If there is an incomplete response after 4 to 8 weeks, consider adding one rescue therapy x 1 dose

Medication	Recommended Dose	Side Effects	Patient Education