title: Stimulation of defecation: effects of coffee use and nicotine on rectal tone and visceral sensitivity.
abstract: OBJECTIVE
  Coffee and cigarette use is believed to induce bowel movements, although the literature is controversial and precise measurements of rectal tone and sensitivity with a barostat have never been performed. The aim of this study was to assess the effects of coffee and nicotine on rectal tone, compliance and sensitivity.
  
  
  METHODS
  Sixteen healthy volunteers were recruited for the coffee (n = 8) and nicotine (n = 8) experiments. The experiments were randomly performed in a placebo-controlled crossover design on separate days. In the coffee experiment, 280 ml strong coffee or warm water was drunk and in the nicotine experiment, nicotine (2 mg) or placebo was given sublingually. A rectal barostat procedure was carried out. A flaccid bag, mounted on a catheter, was inserted in the rectum. Continuous pressure distension was exerted to register basal visceral sensitivity and compliance. After rectal adaptation, the stimulus was given. Rectal tone was measured for 1 h, after which continuous pressure distension was repeated.
  
  
  RESULTS
  Rectal tone increased by 45% 30 min after coffee intake (p = 0.031) and by 30% after water intake (p = 0.032), but the effects of coffee and water were not significantly different. Rectal tone did not change significantly after administration of nicotine (7%) or placebo (10%). There was no difference in compliance and visceral sensitivity between coffee and water or nicotine and placebo.
  
  
  CONCLUSIONS
  Both coffee and warm water have an effect on defecation by increasing rectal tone, but nicotine (2 mg) did not affect rectal tone. Coffee and nicotine did not influence sensitivity or compliance.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Centre, Rotterdam.
authors.forename: Cornelius E J
authors.initials: CE
authors.lastname: Sloots
authors.forename: Richelle J F
authors.initials: RJ
authors.lastname: Felt-Bersma
authors.forename: Rachel L
authors.initials: RL
authors.lastname: West
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Kuipers
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003069:Coffee / Q000009:adverse effects*; D015331:Cohort Studies; D003672:Defecation / Q000502:physiology*; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D008297:Male; D008365:Manometry; D009538:Nicotine / Q000009:adverse effects*; D012007:Rectum / Q000502:physiology*; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity
chemical_list: D003069:Coffee; D009538:Nicotine