Constipation and getting more liquids into ds

[duffster]

DS is 27 weeks and has been weaning for a couple of weeks. Not going too badly but poor little fella has been constipated on and off. I have given him boiled mushed apricots which did the trick, but I would rathr tackle the cause - he battles with me over nearly every bf (too boring) and takes a few sips of water (refuses a bottle, just uses a doidy cup).
Any ideas to get him to love his liquids?

do you give him cucumber, melon and other watery foods? also, banana can be constipating . keep perservering and offer water with his solid food.