I did the FODMAP diet and cut out all things with fiber: so NO chickpeas, lentils, beans, bran, cruciform vegetables(cabbage, Brussels sprouts, cauliflower)
I ate white bread and meat, (lamb, turkey) and no roughage at all and it magically cleared up.
I had the diarrhea type though.
A strong black coffee is amazing for getting things going. I have a small cup every morning. When I detox from coffee a small cup of hot water and lemon has the same effect.
I also eat oat bran now as my breakfast and did a two week fast on Kefir (bioutiful dairies) to recolonise my gut. Worked a charm for the bloating. I also use a probiotic called flat tummy by Optibac.
Using a hula hoop is amazing also.
Hope you find relief soon. IME buscopan isn’t any good to take as it stops spasms in smooth muscle and will stop peristalsis which will make your constipation even worse.
A spoon of Psyllium husks in a large glass of water with a spoon of ground chia seeds might work for you. Squeeze in some lemon juice and a sprinkling of xylitol (sugar from fruit) or honey.