The consistency and colour of your pee and poo can tell you a lot about your health. Also the food you eat can effects the consistency and colour of your poo. For example if you are eating lots of green leafy vegetables the poo may turn green.
The runniness of your poo may mean that you could be insensitive to fructose or due to sorbitol in summer fruit which can cause diarrhoea. So please contact a local GP if this persists.
For more info on what your poo says about your health check this out: https://theconversation.com/health-check-what-your-pee-and-poo-colour-says-about-your-health-59516.