Abdominal twitching/pulsing. Tingling outside anus..

For the past couple of weeks I've been having fleeting twitching, pulsing, fluttering, whatever you want to call it, sensations in the abdomen. I laughed to myself the other day because It's how I imagine a pregnant women feels when the baby moves around or kicks. I've also had a strangle tingling sensation around my anus, and sometimes it feels like it's in the area between my anus and my scrotum.

I'm a 22 year old male, don't exercise much aside from taking my dog for walks. I'm 216 pounds and just over 6 feet tall. My diet consists of a lot of pastas, cold cut sandwiches or things of the like. I always make sure to get in as much fibre as possible, if I feel I haven't had much fibre for the day I'll drink a glass of metamucil. I also eat an activa pro-biotic yogurt on a daily basis.

My abdomen is far from normal. For the past two years I've had almost constant abdominal discomfort. Whether I'm constipated or having diarrhea (both of which almost completely went away after I started pro-biotic yogurt), or gas is rumbling around in there, or it's just uncomfortable , it never ceases. The only pain I've had down there has been very quick to arise and quick to leave, this happens now and then but it's far from intense and doesn't cause me to fall over in pain or anything.

My stool comes out normal, for the most part. Sometimes it's in chunks, sometimes it's solid, other times its the normal kind. I've seen mucus on my stool before, my doctor thought I had a lazy gut or my stomach was creating too much acid and treated me with Nexium because it was coinciding with stomach pain (only when standing /sitting certain ways). After the Nexium that stomach pain ceased, that was half a year ago.

that's all there is to know about me, really, in terms of medical things. I also have asthma, but that's unrelated (I think?) It's mild and I keep it in check with daily doses of Advair, and singulair.

Anyone have any suggestions for me? the tingling around my anus is especially distracting. I've also quite often figured I have anxiety issues, could these be symptoms? Or could I have IBS?

Thank you!