Diarrhea
Diarrhea is an essential symptom of IBS. This happens because of the frequent and powerful contractions of the gut. A feeling of muscle cramps can accompany diarrhea.
The stomach contracts and relaxes in a rhythmic manner to create a normal bowel movement. But this cycle is interrupted in IBS. IBS can either accelerate muscle contractions in the gut or slow them down. And, at different times, IBS can cause constipation and diarrhea. Diarrhea is related to how the gut and brain interact, as with other signs of IBS.