Phenotypic variation of colonic motor functions in chronic constipation.
OBJECTIVE
Colonic motor disturbances in chronic constipation (CC) are heterogeneous and incompletely understood; the relationship between colonic transit and motor activity is unclear. We sought to characterize the phenotypic variability in chronic constipation.


METHODS
Fasting and postprandial colonic tone and phasic activity and pressure-volume relationships were assessed by a barostat manometric assembly in 35 healthy women and 111 women with CC who had normal colon transit (NTC; n = 25), slow transit (STC; n = 19), and defecatory disorders with normal (DD-normal; n = 34) or slow transit (DD-slow; n = 33). Logistic regression models assessed whether motor parameters could discriminate among these groups. Among CC, phenotypes were characterized by principal components analysis of these measurements.


RESULTS
Compared with 10th percentile values in healthy subjects, fasting and/or postprandial colonic tone and/or compliance were reduced in 40% with NTC, 47% with STC, 53% with DD-normal, and 42% with DD-slow transit. Compared with healthy subjects, compliance was reduced (P <or= .05) in isolated STC and DD but not in NTC. Four principal components accounted for 85% of the total variation among patients: factors 1 and 2 were predominantly weighted by fasting and postprandial colonic phasic activity and tone, respectively; factor 3 by postprandial high-amplitude propagated contractions; and factor 4 by postprandial tonic response.


CONCLUSIONS
Fasting and/or postprandial colonic tone are reduced, reflecting motor dysfunctions, even in NTC. Colonic motor assessments allow chronic constipation to be characterized into phenotypes. Further studies are needed to evaluate the relationship among these phenotypes, enteric neuropathology, and response to treatment in CC.
Ravi
Karthik
K
Clinical Enteric Neuroscience Translational and Epidemiological Research Program, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Bharucha
Adil E
AE
Camilleri
Michael
M
Rhoten
Deborah
D
Bakken
Timothy
T
Zinsmeister
Alan R
AR
D000328:Adult; D002404:Catheterization; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage; D002908:Chronic Disease; D003106:Colon / Q000503:physiopathology*; D003187:Compliance / Q000187:drug effects; D003248:Constipation / Q000503:physiopathology*; D003672:Defecation / Q000502:physiology; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008365:Manometry; D009388:Neostigmine / Q000008:administration & dosage; D010327:Pastoral Care; D010641:Phenotype; D019518:Postprandial Period; D011312:Pressure
D002800:Cholinesterase Inhibitors; D009388:Neostigmine