is the feeling that you need to pass stools, even though your bowels are already empty. It may involve straining, pain, and cramping.This is due to colitis (inflammation/infection of the bowel), due to motility disorders, crohn's, ulcerative colitis
Enema and stool softeners will relieve constipation
.If your habits are regular then this is ruled out.
If you continue to have symptoms of tenesmus that are constant or come and go I suggest to meet a Physician/Gastrophysician since it might require a colonoscopy
.Hope this helps.Take care.