There were five symptoms that very few women identified as possibly being due to cancer: vaginal itching or burning, back or abdominal pain, being tired all the time, having to pass urine very badly or more often than usual, and bloating.

MSN: 5 signs of gynecological cancer women ignore

Signs there may be a problem include difficulty or pain when passing urine, the need to pass urine more often, broken sleep due to increased visits to pass urine, waiting for long periods before the urine flows and the feeling that the bladder has not emptied fully.

BBC: Prostate cancer 'diagnosed too late'

Typically, drugs get into the water supply when people flush unneeded medication down toilets or pass trace amounts in urine.

WSJ: Anxiety Drug in Rivers Affects Fish Behavior

Small stones most often pass from the kidney through the ureters and on to the bladder and out with urine.

CNN: What can I do for kidney stones?