It is defined as having hard stools that are difficult to pass.
Frequency is less important.
Some people only pass a normal motion every couple of days while others may pass two or three a day. Constipation is almost always caused by a lack of dietary fibre in the diet. Irregular eating patterns and dieting add to the problem and help explain why constipation is common in women and teenage girls. Many women also become constipated just before their period and this may be due to the interactions between the female hormones and some of the hormones secreted by the gastrointestinal tract. It is also common in some elderly people with poor abdominal muscle tone.