Characteristics of small bowel motility in patients with irritable bowel syndrome and normal humans: an Oriental study.

1. Small bowel dysmotility may be one of the clinical manifestations in Occidental patients with irritable bowel syndrome. Here we studied the characteristics of small bowel motility in Oriental patients with irritable bowel syndrome and identified the factors responsible for disturbed small bowel motility. 2. We enrolled 90 patients with irritable bowel syndrome and 45 healthy controls to the study. The patients with irritable bowel syndrome were further divided according to their predominant bowel habits. Of those, 45 were constipation-predominant and 45 were diarrhoea-predominant. Small bowel transit was measured by the non-invasive hydrogen breath test in the fasting state. 3. The transit times obtained in constipation-predominant and diarrhoea-predominant patients with irritable bowel syndrome and in controls were 108.4+/-34.3, 67. 4+/-19.6 and 85.3+/-37.3 min respectively (P<0.05). Delayed transit characterized constipation-predominant patients with irritable bowel syndrome, whereas accelerated transit was observed in diarrhoea-predominant patients with irritable bowel syndrome. The ages of constipation-predominant and diarrhoea-predominant patients with irritable bowel syndrome and of controls displayed a significant positive correlation with their small bowel transit times (r=0.34, 0.31 and 0.39 respectively; P<0.05) and body mass indexes also demonstrated a positive correlation (r=0.31, 0.41 and 0. 30 respectively; P<0.05). Other demographic characteristics did not influence the small bowel transit times. 4. Accelerated or delayed small intestinal transit is exhibited in Oriental patients with irritable bowel syndrome showing either diarrhoea-predominant or constipation-predominant symptoms. Age and body mass index must be taken into consideration to study patients with suspected small intestinal dysmotility.