Don't take any more stimulant laxatives - senna and bisacodyl (the ingredient in ex-lax) are both potentially addictive and (in my experience) stomach-cramping, diarrhea-inducing.
You do need to drink plenty, make sure you're getting enough exercise, and eat more fruit and veg and less meat and dairy products...
but if you need a "chemical crutch" to keep your bowels working, enemas and suppositories are the best way to go (so to speak), because they don't have to irritate their way all along the intestine and so can bs used frequently (if need be) without concern.
This may sound weird, but it's helped me before when I couldn't go for days at a time, try taco bell food. No joke. Whenever I would get stopped up and eat some taco bell food I literally pooped within a few hours. It's strange, but it worked for me. Doesn't mean it will work for you but it's worth a shot.