Linseed are absolutely fantastic. They are very, very cheap and can be purchased from health shops or online. (even some supermarkets do them)
Sprinkle anything from one to 8 spoonfuls on ANY food that you feel you can. They are relitively tasteless (a little nutty perhaps) and it does not matter too much if you chew them well or they just go down whole.
If i eat a lot of meat/protein (= bad constipation) then a couple spoonfuls of these gets things sorted out. Good luck !