CALCA and inflammatory bowel disease: Specific ion channels on sensory neurons, such as TRPA1, TRPV1 and TRPM8, as well as neuropeptides released by these neurons—including substance P, calcitonin gene‐related peptide (CGRP), vasoactive intestinal peptide and pituitary adenylate cyclase‐activating polypeptide—play distinct roles in the pathophysiology of IBD.