To compare the impacts of electroacu puncture ( EA ) and moxibustion ( Mox ) on the prima ry gastrointestinal symptoms and the expressions of colonic mucosa-associated neuropeptide substance P ( SP ) and vasoactive intestinal peptide ( VIP ) in patients with either diarrhea-predominant or constipation-predominant irritable bowel syndrome ( IBS-D and IBS-C , respectively ) .