The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other impactions and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significantly under represented in the colic population. When compared with the control sample the number of spasmodic/undiagnosed colic cases in the 5–10-year-old group and the number of surgical colics in the over 15-year-old group were significantly greater than expected. No statistically significant correlation was found when the seasonal incidence of colic was compared with monthly temperature, change in monthly temperature, monthly rainfall, and rainfall weighted for temperature.