36 hour fasts and <ahem> digestive transit

[CloseYourEyesAndSee]

So I'm doing 36 hour fasts once a week for health and weight loss, which are easy and great BUT they are messing up my poo schedule which is making me constipated. One week I went 3 days so I took some laxative but I don't want to do that every week! Does anyone else do full day fasts and found this to be an issue? What did you do?

Are you drinking enough? You could try fasting salts, they always get things moving although you don't need them on a short fast like that, they could help. The other thing you can take is psyllium husks which are absolutely disgusting but will maintain gut
Motility.

are you really constipated or just don't go for a while?
of course not eating for some time means there is nothing to transit.
how much fibre do you get when you do eat? maybe add a chia seed 'pudding' with yoghurt and dried fruit once a day?
and definitely keep up with drinking plenty.