This is Dr. David
I am sorry you have been having diarrhea.
sometimes taking Imodium can cause constipation and hard stools which can cause pain as the hard stool travels through your bowels.
if you have localized pain, you should see a doctor and get your abdomen examined.
sometimes diarrhea itself can cause bowel spasms and cramps and pain which is localized.
is it localized to upper or lower abdomen on the left side?
yes, diarrhea can often cause bowels to cramp and cause mild localized pain
usually it gets better with time as the diarrhea gets better.
you are welcome
I hope you feel better.