Altered bowel habit and constipation

At a glance

• Altered bowel habit is a change from a person's normal pattern. A new, persistent change in an adult, especially with bleeding, weight loss or iron deficiency, needs colonoscopy to exclude colorectal cancer.
• Chronic constipation affects about 1 in 7 adults, more women and older people. Most is primary (normal transit, slow transit or a defecatory disorder), but always look for drugs and metabolic causes.
• Treat stepwise: lifestyle and fibre, then macrogol, then a stimulant, then prucalopride or a secretagogue. Think of a defecatory disorder when laxatives fail.