Constipation can increase the chances of bladder infections in two ways. First, if stool gets stuck in the rectum, it inhibits the emptying of the bladder, which can cause some
people to retain urine. Urine retention leads to stagnant urine, which is a breeding ground for microbial growth, which will lead to a bladder infection.
The other way that constipation can lead to bladder infections is if someone takes too many laxatives to treat the constipation, they can get diarrhea. Diarrhea stool can easily contaminate the perineal area, since the rectum is only a few inches from the urethra, the opening of the bladder. Also, after female menopause, there is a decrease in the protective normal vaginal bacteria, so if stool bacteria gets into that area it can easily grow and travel into the bladder.