Soften hard stool and check difficulty emptying
I ask about stool consistency, straining and the feeling of blockage. Hard stool often improves with food changes or a laxative. If soft poo is still difficult to pass, I consider whether the muscles used to empty the bowel are coordinating properly.
Soluble fibre such as psyllium can help some people. Macrogol and stimulant laxatives such as senna or bisacodyl are other options. I review what you have tried, the dose and response before changing treatment. Persistent emptying difficulty may need bowel-function tests and specialist biofeedback.
Hard stool, difficult emptying or both?
Stool and water
The large bowel absorbs water. Slower passage can make stool harder, but some people have difficulty emptying even when stool is soft. Drinking extra water alone does not fix every cause.
Stool and water
The large bowel absorbs water. Slower passage can make stool harder, but some people have difficulty emptying even when stool is soft. Drinking extra water alone does not fix every cause.
How emptying works
The rectum, pelvic floor and anal muscles need to coordinate. If the outlet does not relax properly, specialist testing and retraining may help. Treatment may involve learning to relax these muscles, rather than simply strengthening them.
Why loose leakage can occur
Sometimes liquid stool leaks around retained hard stool. This can be mistaken for diarrhoea. Your GP may need to examine you before changing laxatives or adding an anti-diarrhoeal medicine.
Choosing treatment
I review medicines, stool consistency, emptying and any warning signs. Food and toilet changes, laxatives and pelvic-floor treatment have different roles. Persistent symptoms need a planned review.
Simplified illustrations, not to scale. These show an example, not your own anatomy or test result.
Read every diagram explanation
Stool and water
The large bowel absorbs water. Slower passage can make stool harder, but some people have difficulty emptying even when stool is soft. Drinking extra water alone does not fix every cause.
How emptying works
The rectum, pelvic floor and anal muscles need to coordinate. If the outlet does not relax properly, specialist testing and retraining may help. Treatment may involve learning to relax these muscles, rather than simply strengthening them.
Why loose leakage can occur
Sometimes liquid stool leaks around retained hard stool. This can be mistaken for diarrhoea. Your GP may need to examine you before changing laxatives or adding an anti-diarrhoeal medicine.
Choosing treatment
I review medicines, stool consistency, emptying and any warning signs. Food and toilet changes, laxatives and pelvic-floor treatment have different roles. Persistent symptoms need a planned review.
What I ask about your bowel movements
There is a wide range of normal bowel frequency: some people go several times a day and others every few days. Constipation usually means stools are infrequent or hard, or that you feel blocked or incompletely emptied.
It becomes a problem when it starts to interfere with daily life and functioning. A short bowel diary can record stool form, emptying and any laxatives you use.
Constipation can overlap with IBS when recurring abdominal pain or discomfort is linked to the bowel pattern. That distinction helps guide treatment, but the two conditions are not separated by frequency alone.
Check medicines and possible causes
Constipation can follow changes in routine, eating, activity or fluid intake. Medicines can contribute, including opioid pain relief, iron and some medicines for bladder symptoms, mood or blood pressure.
Other possible contributors include an underactive thyroid, neurological disease or pregnancy. Tests are selected from your history and examination, rather than a standard large panel for everyone.
Do not stop prescribed medicines yourself. If an opioid is necessary, discuss a preventive bowel plan with the prescriber rather than relying on extra fibre alone.
Tell your GP or pharmacist if you are pregnant or breastfeeding before choosing treatment. I may examine the abdomen and, with your consent, the rectum to check for retained stool or an emptying problem.
Constipation alone does not usually mean there is a serious condition in the colon. I may recommend colonoscopy if there is bleeding, unexplained iron deficiency, weight loss, a persistent new bowel change, relevant family history or another reason for investigation.
Increase fibre gradually and drink regularly
If fibre intake is low, increase it gradually and see how you respond. Psyllium is one option, taken with adequate fluid according to its instructions. It may be unsuitable with swallowing problems or suspected narrowing. More fibre can worsen bloating or an unrecognised stool blockage.
Fresh green kiwifruit can help constipation. This has been studied in a trial that included New Zealand participants. You could try it if you enjoy and tolerate it; the evidence for fresh fruit does not apply to every supplement. Coffee, including caffeinated coffee, can stimulate a bowel movement in some people and may help constipation.
A morning cup is reasonable if you tolerate it; decaffeinated coffee may also help. Too much caffeine can worsen urgency, diarrhoea or reflux. Drink regularly, but there is no need to force large amounts of water. Follow any fluid restriction for heart or kidney disease.
A comfortable toilet routine
Try going after a meal, when eating naturally stimulates the bowel. Respond to the urge when you can, allow yourself some privacy and avoid prolonged straining. A small footstool, with your feet supported and knees a little higher than your hips, can make the position more comfortable.
Regular movement can help. Tell me if pain, limited mobility or difficulty getting to a toilet at work is affecting your bowel routine, so we can take this into account.
How laxatives work
Needing prescribed laxatives does not mean your bowel is damaged or addicted. Some chronic constipation needs regular treatment. I review the choice, dose and duration because cramps, diarrhoea, dehydration or electrolyte problems can occur.
Mix sachets as directed and ask about interactions or other health conditions. Do not keep increasing treatment if you have severe pain, vomiting or signs of obstruction.
| Option | How it helps | Practical point |
|---|---|---|
| Psyllium husk (Konsyl-D, Metamucil, Mucilax) | Soluble fibre holds water and helps stool consistency. | Start gradually with the recommended fluid. It is not a treatment for an impacted or obstructed bowel. |
| Macrogol (Movicol, Molaxole) | An osmotic laxative holds water in the stool. | Mix as directed; adjust the dose with advice if stools become too loose. |
| Senna (Senokot) or bisacodyl (Dulcolax) | Stimulate bowel movement. | Can be used as rescue treatment or in an agreed regular plan; cramps can occur. |
| Pelvic-floor biofeedback | Retrains coordination and relaxation when an emptying disorder is confirmed. | Stronger laxatives alone may not resolve this problem. |
| Prucalopride (Resotrans) | A prokinetic that can help bowel movement in selected chronic constipation. | Specialist use only when other treatments have not helped; prucalopride is not funded in New Zealand. Other prokinetics may be considered in selected cases. |
Loose leakage can occur around retained stool
A build-up of hard stool (faecal impaction) can allow watery poo to leak around it. This can look like diarrhoea even though emptying is poor. It needs assessment and an appropriate clearing plan, followed by prevention.
Do not assume all loose stool is overflow, or automatically take loperamide when you have been constipated and are now leaking. Adding fibre or trying to remove the stool yourself may cause problems. Your GP or specialist can check for retained stool and a possible blockage before choosing treatment.
When soft poo is still hard to pass
The pelvic floor and anal muscles need to relax and coordinate with the pushing effort. In a defecatory disorder, they may tighten at the wrong time. More laxative alone may not correct this.
Selected tests, such as anorectal manometry and balloon expulsion, assess how emptying works; transit tests answer a different question about movement through the colon.
Specialist biofeedback trains coordination and relaxation. It is not simply a programme of strengthening squeezes for everyone. If treatment has not helped, I review the dose and duration, possible secondary causes and emptying before describing constipation as resistant to treatment.
Constipation alone does not usually indicate a sinister colonic problem. I may consider colonoscopy when there are appropriate symptoms, examination findings, a persistent new change or a screening need.
Do not treat possible obstruction at home
Severe or worsening pain, a swollen abdomen, repeated vomiting and inability to pass wind or poo need urgent medical assessment. Do not add fibre or take more laxatives while seeking help for possible obstruction.
Bleeding, unexplained weight loss, iron deficiency or a persistent new change in bowel habit need review. Watery leakage with suspected retained stool also needs assessment.
Call 111 if you collapse or are too unwell to travel safely. Do not wait for a routine appointment or an email reply.
Three things to remember
- Constipation includes hard stool, straining and incomplete emptying, even with daily bowel movements.
- Treatment may soften poo, help it move through the bowel or help the muscles relax during emptying. I choose it according to your symptoms.
- Severe pain, vomiting or inability to pass wind needs urgent assessment. Ongoing difficulty passing soft poo may need tests of the muscles used to empty the bowel.
Related information
Sources and further reading
English clinical master checked 16 October 2026.
- bpacnz: constipation management (2019, older-adult focus)
- Healthify: constipation in adults
- My Medicines, Health NZ Waitaha: macrogol
- Medsafe: macrogol consumer medicine information
- AGA/ACG: chronic constipation pharmacology guideline (2023)
- AGA: refractory constipation expert review (2026)
- AGA: patient information on persistent constipation (2026)
- Gearry and colleagues: fresh green kiwifruit trial (2023)
- Rao and colleagues: biofeedback randomised trial (2010)