TRPM8 and irritable bowel syndrome: The expression of TRPM8 has also been described in tissues that are not exposed to the environment such as the brown adipose tissue where it has a role in thermogenesis and high-fat diet-induced obesity [14], intestinal epithelium associated with irritable bowel syndrome (IBS) and colitis [15,16,17], and the bladder associated with cooling-reflex, urinary urgency, overactive bladder and painful bladder syndrome [18,19,20,21].