Traumatic stress can be associated with adverse mental and physical health outcomes (Friedman & Schnurr, 1995; Lamprecht & Sack, 2002). Whereas the impact of traumatic stress on mental health is typically referred to as posttraumatic stress disorder (PTSD), there is a wide range of somatic symptoms and syndromes related to different organ systems that have been reported in association with trauma. These include cardiovascular, gastrointestinal, dermatological, ophthalmological, and gynecological symptoms (Friedman & Schnurr, 1995). Pain problems figure prominently amongst patients' complaints including headaches, musculoskeletal pain, chest pain, abdominal pain, and pelvic pain. Somatic symptoms have been reported after different types of trauma, including sexual abuse, and natural disasters, and have been reported after every military conflict since 1864. This chapter will discuss the relationship of traumatic stress with somatic symptoms focusing on so-called medically unexplained or “functional” syndromes, in particular, irritable bowel syndrome (IBS) and fibromyalgia (FM). Both syndromes are commonly reported by PTSD patients, and affected patients frequently show comorbidity with disorders of mood and affect (Campbell, Clauw, & Keefe, 2003; Mayer, Craske, & Naliboff, 2001; Williams, Brown, Clauw, & Gendreau, 2003).
Somatic responses associated with normal emotions and somatic manifestations of traumatic stress can be conceptualized as normal and pathological outputs of the emotional motor system (EMS; Figure 7.1; Holstege, Bandler, & Saper, 1996). The EMS refers to brain circuits generating parallel outputs to the body and brain that mediate the distinct pattern of the organism's response associated with emotional activation.