Are you constipated? Bladder neck obstruction, stone or ureterocele. Congenital remnant of urachus can remain connected between bladder dome and umbilicus as a fibrous thread or bladder diverticulum. Urethral stricture or prostatic obstruction in men or cystocele or uterine prolapse in women. Suggest you consult urologist provided constipation has been excluded. Good luck.