Extreme pain. An expected part of a bladder infection is a pain in the process of urination, but not many people know that pains can also be experienced in other areas of a person’s body. Sometimes, a person suffering from a bladder infection will experience intense pains in the lower areas of the torso, both in the front and in the back of the body. Spreading pain might indicate complications. If the side begins to ache underneath the ribs, it might mean that the infection has spread to the kidneys.