Diet and lifestyle for management of constipation in adults
To improve bowel activity, adults should be encouraged to modify lifestyle factors that can contribute to constipation, if present (see Causes of constipation in adults). Physical activity is encouraged because it reduces intestinal transit time and stimulates regular bowel movements.
Patients should be encouraged to respond to an urge to defecate, especially after meals or on waking. When seated on the toilet, correct positioning (ie with knees above the level of the hips to reduce the rectal angle—a footstool may be needed) is important.
In addition to addressing lifestyle factors, review the patient’s diet to ensure it contains adequate noncaffeinated fluids; adequate hydration is important for optimal bowel function. Although constipation is not always associated with a low fibre intake, generally it is considered appropriate to begin therapy with a trial of increased fibre and fluid.
The recommended dietary fibre intake for adults is 25 to 35 g daily1Reynolds, 2019. Increase the fibre content of the diet gradually to avoid adverse effects such as bloating or flatulence. Patients should be encouraged to choose a variety of foods containing insoluble and soluble fibre (eg fruit and vegetables; wholegrain or wholemeal products such as breads, cereals, pastas and rice; legumes; seeds and nuts) rather than eating a few very high-fibre foods (eg unprocessed bran).
Foods high in insoluble fibre (eg wheat bran) and polyols (eg prunes, pears, stone fruit) are often recommended and may be beneficial for some patients; however, for patients with irritable bowel syndrome, these foods can make symptoms worse (see Initial dietary therapy for irritable bowel syndrome and Fibre in irritable bowel syndrome).
There is some evidence that kiwifruit, which is high in poorly fermentable fibre, is beneficial for treating mild constipationEady, 2019Weir, 2018Kindleysides, 2015Ansell, 2015.
See Types of fibre and their role in irritable bowel syndrome for the types of fibre and their effect on the bowel.