HELP bowel problems

So the past 2 days I have been really constipated and I have a gas build up and I am barely able to get it out. I have IBS I believe but what worry me is the constant pressure I am feeling on my lower abdominal area. I was Kinna in distress this morning before I had a bowel movement. Was painful . I am wondering what I can do about this as it is making me Kinna not want to eat . Before this I was having no problems.

Can anyone relate or help with a solution to this that ISN'T over the counter medication. I also have 1 cup of coffee a day and for the past 3 days it isn't helping.