I have found juicing vegetables to be the answer for my constipation problems which stretched back over a decade. Typically I would go for 3-4 days with nothing happening. Psyllium husks worsened things considerably. Two to three tablespoons of olive oil with some freshly squeezed orange juice gave me suboptimal results but better than nothing.
From the day I started juicing a quarter of cup of mixed veges three times a day before meals I became regular. I didn’t start juicing with constipation in mind but to get more goodness into me minus the fibre. Nature even calls mid breakfast these days! I was amazed given my poor track record of the previous decade. To test if my success was all about the juicing I stopped it for two days and became constipated. It took two days of juicing again to get me back on track and it was like turning on a light switch. I’m still in awe actually. I dropped all grains from my diet last December so in my case eating grains did not contribute anything positive to my constipation woes and possibly worsened them. I may experience the odd day of not being regular but to date it is only every now and then.
I bought a cold press juicer to get the maximum nutrition from juicing. Centrifugal juicers create heat which is said to destroy some of the goodness of the veges in the process.
I’m not taking any probiotics products but do eat small amounts of yoghurt after each meal at the moment.
If you get really stuck (no pun intended) with this problem, juicing veges could be the answer.