We have studied the bowel habits of a theoretically normal working pop
ulation to know the range defecation patterns, characteristics and mai
n factors that may influence it. We have designed a questionnaire comp
osed of 80 questions and distributed to 837 people. Answers, were eval
uated in 414 cases (187 men and 227 women), with a median age of 33 ye
ars (range 20-64 years). The average number of stools was 7.1 +/- 3,3
per week and in 62.4% of subjects they were between the range of 5 and
8. Rowel movements were less frequent in women than in men, and the s
ame finding was seen about self-reported constipation; nevertheless th
ere were no differences in regard to age. Laxatives were used regularl
y by 11.3%, and 36% referred straining at stool at least 25% of the ti
me and 8.3% referred straining for loose stools. Alternating bowel fun
ction presented in 19.4% and functional abdominal pain in 28% with a f
emale predominance. Faecal incontinence occured in 6.8% of population;
an important prevalence. We also analyse variables such as diet influ
ence, physical activity, obstetrical, gynaecological and psychosocial
factors. Although this survey has revealed that a normal bowel functio
n is very variable, only a 7.5% of the subjects, consulted a doctor fo
r bowel complaints.