The primary factors differentiating chronic constipation from constipation-predominant IBS (IBS-C) is the presence of pain, extraintestinal symptoms and psychological comorbidity (associated with IBS-C). Evidence indicates that abdominal pain has more pathogenic mechanisms than those associated with constipation, in particular in patients with IBS, and medications with specific neuromodulatory analgesic properties are partly needed to improve discomfort and pain associated with constipation (particularly for those with IBS-C).