10 month old. She's bf plus solids and some cow/formula. She has a cold and with the humid weather too has become v bunged.
She's never pooed every day except one bout of the runs.
However this time it was - Full poo last Thurs, nothing over whole weekend then tiny/hard pellet poos Mon, Tues and Today.
I've been giving weetabix, prunes, extra drinks (did nothing). Tummy massage etc.
GP suggested oiling her bum with vaseline but said no to lactulose prescription as she thought it was mild.
Pharmacist was aghast and said it sounded severe and sold me lactulose.
The problem is I get very anxious about weight gain and she's off her solids with the cold and constipation. 
How long before the lactulose kicks in - in your experience?
And how do I get fibre and water in to push things through. She only wants boob/bottle atm.