Does normal effort cause flare ups?

Last Thursday and Saturday, I ran some errands, and saw the gynecologist on Saturday. I stayed outdoors for around 4 or 5 hours. Yesterday, I woke up with severe, voluminous diarrhea to the extent that I felt dehydrated. I took Imodium and went to work w severe nausea. In the afternoon, the nausea increased and I took a Zofran injection. After 3 or 4 hours, the effect of Zofran wore off and I took another Alizapride injection. The cause of nausea could be that my stomach has been hurting me lately and I have cut off a lot of the vitamins I take and I'm taking only my essential Crohn's and GERD meds. This happens always coz of pentasa and Entocort. The time nausea was under control I started to have severe colon cramps. It's normal that I have cramps but I realized lately that whenever I exert a lot of effort and run errands that require more than 2 hours driving, I become sick. Today, I didn't go to work as there are severe cramps. At work, as I am staying in one place, I can bear up with the effort and stay there for 8 hrs/day. Things are different when I have to go out. I started to fear going out w friends and become more of an introvert.
Does exerting effort cause you a flare up?
Your replies are highly appreciated.