How To Treat Constipation?

I have had a bowel movement every morning for years im coming up on my thirtth birthday in October. I go now three or four days without a movement and my belly bloats out,i have tried fiber tablets and stool softner when I took the softner I had runny and water movement which was weird considering I hadn t gone for three days.what should i do or eat to try to get back to being normal is it stress or anxiety