What does science say about controlling urination, and other bodily functions? We tackle three queries about peeing triggers, pooing positions and missing sweat. This episode CrowdScience presenter Marnie Chesterton poses some of the best listener follow-up questions that have landed in our inbox to a panel of experts. Listener Samuel in Ghana is wondering why watery sounds seem to induce urination. Producer Melanie Brown heads out to survey whether this is the case for individuals in an actual crowd at a public fountain in London. And urologist and trustee of the International Continence Society Marcus Drake talks Marnie through how he uses the sound of running water during his work as a hospital doctor helping patients with common but distressing peeing issues, and the limitations of research into this question. And he’s not the only listener who wants us to dig deeper into topics we’ve explored on the show before. Anna in Tokyo also got in touch after hearing our show about toilets, to ask if there is a toilet design that is most ‘natural’ for our health. Gastroenterologist Anton Emmanuel explains why small changes in people’s posture whilst pooing can have a significant impact on their quality of life. Finally, listeners Stelle, James and Joel emailed crowdscience@bbc.co.uk after hearing Marnie investigate hyperhidrosis: Sweating too much. They and their relatives experience the opposite: