Bladder spasms are contractions of the bladder which may be painful.They may be caused by aurinary infection,weak muscles of the pelvis,due to child birth or surgery. In some cases it occurs due to medicines. Natural remedies you can try Apply Dhanvantram oil on lower abdomen every night before sleep. Take 2 tsp of VASYANTHAKA gtm at bed time. Do yoga exercises to strengthen the pelvic muscle. Regular hiip bath and hydro therapy also helps.