Has this happened all of a sudden? Do you often have diarrhoea and cramps? Do you pass blood or mucous (this might indicate inflammation in the bowels)? If it is a bug, it needs to get out and you should not take Imodium. You might have actually made it worse by keeping it in, your body is trying to get rid of it but the Imodium is preventing it?
Not that you might have it, but as you have not said if this is a regular thing or something that just has happened this week, I might mention it in case others are reading the thread with similar symptoms. If it is an inflammatory disease, such as Ulcerative Colitis or Chron's, the Imodium can actually make it worse. The symptoms probably would not be just the loose stools, you might have cramps to the right of the belly button, or your back passage would feel like on fire, you would have sudden urgency to go to the bathroom, maybe even going as much as 20+ times in a day, you might pass blood or mucous, when formed your stools might have black streaks, your tummy might be bloated as if you were 3 months pregnant, your joints might hurt as if you had arthritis, etc.
Don't take Ibuprofen and stay with the Paracetamol, as Ibuprofen can hurt the lining of the stomach and aggravate the pain. I also suggest a hot water bottle, camomile or peppermint tea, and a visit to the GP on Monday if you continue to experience pain and diarrhoea. I hope you get better soon, it is really not nice x