Peppermint oil. Maintaing regular bowel movement with fiber and exercise are good. For immediate relief you can try peppermint oil.
Medications. Besides dietary and lifestyle modifications, there are classes of medications that may help with spastic colon especially if diarrhea is associated. These include anticholinergic agents such as Bentyl and levsin (hyoscyamine). At times low does tri-cyclic antidepressant medications work as well.
Diet and fluids. And probiotics seem to help if patient is compliant. Eat a high fiber diet, regular meal times and portions and drink 80-100 oz of caffeine free, alcohol free fluid daily.