To determine bowel patterns and the prevalence of defecation difficulty in young university students, we administered a self-reported questionnaire to 1,617 college students about their bowel habits and eating patterns and obtained the following: 83.7% showed defecation frequency between 2 times per day and 3 times per week, and 33.4% reported difficulty in defecation. Among the subjects with defecation difficulty, 69% complained of constipation and 31% of diarrhea. It was also shown that the prevalence of self-reported defecation difficulty varied by sex. Women were more likely to have defecation difficulty than men (OR=2.5; 95% CI: 2.005-3.149). There were also differences between men and women in respect to the bowel habits (frequency, regularity, thickness, volume, form and time required) and food preferences. Men reported a higher frequency of defecation than women (p<.001). The dietary fiber intake volume of the subjects with defecation difficulty was smaller than subjects without the problem (OR=0.83, CI; 0.706-0.978). Moreover, those whose favorite food was meat were more likely to have defecation difficulty than those preferred vegetables (OR=1.39; 95% CI: 1.058-1.820). Irregular defecation was reported in 44.5% of the students, especially non-residents of Cheolla province (OR=1.2; 95% CI: 1.007-1.480). Non-residents ate dietary fiber significantly less than residents and there were some differences in diet habits and also in bowel habits.