Objectives The aim of the study was to describe faecal consistency, prevalence and risk factors for diarrhoea and constipation in a rescue cat population. Methods Faecal samples in litter trays from a stratified random sample of cats in pens at 25 UK rehoming centres were scored for consistency in two discrete time periods, summer and winter. A six-point scale was used, with diarrhoea ⩽3, severe diarrhoea ⩽2 and constipation as 6. The effect on faecal consistency of age, number of cats per pen and season was investigated using multivariable hierarchical logistic regression with centre and pen as random effects. Intraclass correlation coefficients were used to estimate the effect of pen and centre. Results Overall, 11.9% (95% confidence interval [CI]:10.4-13.7) of cats had diarrhoea, 2.4% (95% CI 1.6-3.7) had severe diarrhoea and 5.6% (95% CI 4.2-7.5) were constipated. The prevalence of diarrhoea (median 11.0%, interquartile range [IQR] 5.0-14.5%) and constipation (median 4.2%, IQR 1.8-5.9) varied at the centre level. Diarrhoea was associated with being a kitten (odds ratio [OR] 2.54, 95% CI 1.45-4.46; P = 0.001) and being in a multi-cat pen (OR 1.24, 95% CI 1.04-1.48; P = 0.02) but not with season (OR 0.99, 95% CI 0.55-1.77; P = 0.96). Severe diarrhoea was associated with senior cats (OR 4.66, 95% CI 1.25-17.44; P = 0.02). Constipation was associated with increasing age (OR 1.01; 95% CI 1.00-1.01; P = 0.02) and winter (OR 0.43, 95% CI 0.21-0.89; P = 0.02). Both diarrhoea and constipation showed moderate correlation with pens within a centre. Conclusions and relevance From IQRs, we suggest acceptable levels for diarrhoea and constipation of 11% and 4%, respectively, targets of 5% and 2%, and intervention at 15% and 6%. Increasing age was associated with decreased risk of diarrhoea and increased risk of constipation. However, severe diarrhoea was associated with being a senior cat. Season (winter) was a risk factor for constipation; multi-cat pens were a risk factor for diarrhoea. Describing the prevalence and risk factors for diarrhoea and constipation in cats will assist their management in this population. Understanding and managing constipation may be more important than interventions to reduce severe diarrhoea.