Private constipation in adults clinic in London, same-day gastroenterology.

Common causes

• low fibre, low fluid intake, and inactivity
• medicines — opioid painkillers including codeine, iron tablets, some antidepressants, antacids containing aluminium, and certain blood pressure tablets
• ignoring the urge, or lack of a private toilet at work
• an underactive thyroid, diabetes, low potassium or high calcium
• pregnancy, and the postnatal period
• irritable bowel syndrome, and pelvic floor dysfunction

Which laxative

• Bulk-forming (ispaghula, methylcellulose) — first choice for most people. Must be taken with plenty of fluid, and are unsuitable for opioid-induced constipation or where evacuation is the problem. Takes two to three days.
• Osmotic (macrogol, lactulose) — draws water into the stool. Macrogol is generally preferred; lactulose commonly causes bloating and wind. Takes one to three days.
• Stimulant (senna, bisacodyl) — makes the bowel contract. Works within 8 to 12 hours. Useful short-term and for opioid-induced constipation. Long-term daily use is no longer thought to damage the bowel, but it is still better to establish a regimen with an osmotic base.
• Suppositories and enemas for hard stool in the rectum, or where oral treatment has not worked.
• For opioid-related constipation, start a stimulant plus osmotic laxative at the same time as the opioid rather than waiting.
• Newer prescription options exist for chronic constipation not responding to standard laxatives.

Practical measures

Positioning

Sitting with the knees higher than the hips — using a small footstool — relaxes the muscle that maintains continence and straightens the passage. Lean forward with elbows on knees, keep the back straight, and breathe out rather than holding your breath and bearing down. This alone helps a great many people and costs nothing.