Is coffee a colonic stimulant?
Level 2 - randomized trial
Individual randomized crossover physiological trial in humans
PubMed 9581985 · doi:10.1097/00042737-199802000-00003
What was done
Twelve healthy subjects underwent ambulatory colonic manometry using a six-sensor solid-state probe placed up to the mid-transverse colon. Over a 10-hour period on the following day, participants received four stimuli in randomized order: 240 ml of caffeinated black Colombian coffee (containing 150 mg caffeine), 240 ml of decaffeinated coffee, 240 ml of water (all drinks at 45 °C), and a 1000 kcal meal. Motor activity responses across colonic segments were measured.
What was found
Caffeinated coffee, decaffeinated coffee, and the 1000 kcal meal all induced more colonic activity compared with water, demonstrating a greater area under the curve of pressure waves (P < 0.01) and a greater number of propagated contractions (P < 0.05). Activity was greater in the transverse/descending colon compared to the rectosigmoid colon (P < 0.05). Caffeinated coffee stimulation was comparable in magnitude to the 1000 kcal meal, 60% stronger than water, and 23% stronger than decaffeinated coffee. Decaffeinated coffee effects did not differ significantly from water or caffeinated coffee, but were significantly lower than the meal (P < 0.05).
Why it matters
This study provides direct manometric evidence in humans that caffeinated coffee acts as a potent colonic stimulant with an effect comparable to a full meal, driven in part by caffeine.
Limits
The sample size is very small (n = 12) and limited to healthy volunteers, preventing extrapolation to clinical populations with gastrointestinal motility disorders. The abstract does not provide absolute baseline and post-stimulus numerical values or confidence intervals.
Cited by
- supports Eating a meal, exercising, and drinking coffee all stimulate colonic contractions.