Irritable bowel syndrome in man is not a single entity but has several causes. One of the most common forms has similarities with colic and laminitis in horses. Undigested food residues may pass from the small intestine into the colon where bacterial fermentation produces chemicals that lead to disease. In equines the consequences may be disastrous, but in healthy man, such malabsorption may not be harmful. After events such as bacterial gastroenteritis or antibiotic treatment, an imbalance of the colonic microflora with overgrowth of facultative anaerobes may arise which leads to malfermentation and IBS. It is not known whether such subtle changes may likewise be present in the microflora of equines who are susceptible to colic and laminitis. Metabolomic studies of urine and faeces may provide a suitable way forward to identify such changes in the horses gut and thus help to identify more accurately those at risk and to provide opportunities for the development of improved treatment.