1.   In line with these uncertainties measurements of colonic pressures in the irritable bowel syndrome produce contradictory data and no common underlying abnormality has been defined.

2.   Grouping patients according to gross, fairly imprecise symptoms such as predominant diarrhoea or constipation, is perhaps unlikely to uncover a common pathological abnormality.

3.   The most common abnormality in our patients was isolated impairment of prolonged squeezing.

4.   Common functional abnormalities of this condition include reductions in forced vital capacity, carbon monoxide diffusing capacity, and oxygen partial pressure.