The large intestine is the last part of the digestive tract. It absorbs water and dietary substances. However, it is also where most of our bacteria are resident. These bacteria are important for our health and influence many different diseases, including Colon Cancer, Ulcerative Colitis and Crohn's disease. The gut bacteria can also potentially influence responses to treatments in other cancers by helping to change the responses to radiotherapy and chemotherapy. The interactions between these bacteria and the rest of our cells are only now becoming understood and there is little research on the interactions between these bacteria and cancer radiotherapy treatments in pelvic cancer. We will therefore explore this in more detail. We will ask for samples of the patient's poo before their treatment for pelvic cancers. This will include patients with bladder, prostate, cervical, ovarian, womb or colorectal cancers. By doing so we will be able to compare the profile of gut bacteria with responses to treatments, thereby increasing our understanding of the colonic bacteria. To do this we process the poo specimens to remove the bacterial genetic material (DNA) of the bacteria and process it on a machine to read the genetic code and also study the metabolites that they will produce. We can then make a direct comparison between different samples of the relative numbers of different bacteria present. In some cases, we will compare this to metabolites and inflammatory and immune markers identified in a blood sample. This work might help future patients by determining what are the best bacteria to have in the colon during cancer treatments. These could potentially be given to patients, before their cancer treatment, in the form of probiotic medications, should there be an improvement demonstrated in our research. Alternatively we could alter the patients' intakes of specific dietary fibres to boost these bacteria specifically.