something irritated your intestines. Listen to your body, as you have (it seems) and try to eliminate foods that upset your stomach, make you gassy, cause diarrhea. If it stays, bloody stool, I would see your dr. and get a referral to a good gastrointestinal doc (primary family docs don't know anything about gi issues... usually) and they will run tests.
Modifying your diet and listening to your body after you eat, does help and makes a huge difference.
Malyss, Cake is good is correct. I have had this disease for 20+ years. Our bodies do not want to be sick and I believe the autoimmune diagnosis is pure crap. I have eliminated lactose, artificial sweeteners, food that are too rich or sweet and I have been medication free for 90% of my 20 years with this disease. Immodium is a very bad idea. Your body is trying to rid it's self of an irritant and the bowel is not working efficiently, so to artificially hold in the insult is a very bad idea. Start by cutting out lactose, stop drinking milk, cream in coffee, cheese etc. I may seem hard but it can dramatically change you life. The majority of people in the world cannot digest lactose.
I don't think you have to go all tree hugger and meditate for 4 hours a day but you have to eat properly, get some sleep and when you are feeling better some exercise. And cut out the aspartame it is not digestible by the human body. It is usually not an issue but when your colon looks like it's been sunburned and is working at 40% efficiency this complex molecule is like sandpaper on a blister.
I also find that the legumes, beans, soy etc are best to avoid until your back to 100%. It is very off putting and scary to see blood in the bowl and I have found the only thing that will heal my bowel when it has been inflamed in the past was a medication called Salofalk enemas. Not the preferred method to take medication and sometimes it is hard to hold in when the bowel is on fire, but it works for me. The only thing is you have to get the diet in order as well as take the meds. Good luck