Hi. I take Ritalin aka methylphenidate and have for over 10 years. Yes it makes me feel like I have to poop almost immediately, but the problem is my phobia...if someone is in my apartment with me or I am in their home or in a public restrooom its a no go no matter how bad I have to poop. To the point where I get sick to my stomach and constipated and so forth. This phobia debilitates my ability to have close relationships with people or even have a dinner and a movie date. I wish I could get over this crap. No pun intended.