[Diagnosis of Chronic Constipation].

Patients with chronic constipation (CC) usually complain of mild to severe symptoms, including hard or lumpy stools, straining, a sense of incomplete evacuation after a bowel movement, a feeling of anorectal blockage, the need for digital maneuver to assist defecation, or reduced stool frequency. In clinical practice, healthcare providers need to check for 'alarm features' indicative of a colonic malignancy, such as bloody stools, anemia, unexplained weight loss, or new-onset symptoms after 50 years of age. In the Seoul Consensus on the diagnosis and treatment of chronic constipation, the Bristol stool form scale, colonoscopy, and digital rectal examination are useful for objectively evaluating the symptoms and making a differential diagnosis of the secondary cause of constipation. If patients with CC improve to lifestyle modification or first-line therapies, the effort to determine the subtypes of CC is usually not considered. On the other hand, if conventional therapeutic strategies fail, diagnostic testing needs to be considered to distinguish between the different subtypes of functional constipation (normal-transit constipation, slow transit constipation, or defecatory disorder) because these subtypes of constipation have different therapeutic implications and a correct diagnosis is critical. In the Seoul consensus, physiological testing is recommended for patients with functional constipation who have failed to respond to treatment with available laxatives (for a minimum of 12 weeks and recommended a therapeutic regimen) or who are strongly suspected of having a defecatory disorder. The Seoul consensus contains statements of physiological testing, including balloon expulsion test, anorectal manometry, defecography, and colon transit time.