Biomedical subjects

K Welcher

Publications and source records attributed to K Welcher.

3 recordsLinked to original sources

PubMed1999

FECOM: a new artificial stool for evaluating defecation.

OBJECTIVE: Traditionally, barium paste has been used for performing defecography. Because this substance is not stool-like, barium defecography may not accurately represent defecatory function. Our aim was to prospectively compare the utility of a new artificial stool, "FECOM"--a silicon-filled and barium-coated, deformable device the shape and consistency of which mimicked a normal formed stool with that of barium paste. METHODS: Defecography was performed after placing FECOM or barium paste in a random order in 12 healthy subjects (two men and 10 women). We evaluated the changes in anorectal angle, rectal morphology, rectal sensation, and the subjects' preference for a "stool-like" device. RESULTS: Anorectal angle at rest, during squeeze, cough, and straining were each greater with the FECOM when compared with the barium paste (p < 0.006). Anterior rectocele (nine), mucosal intussusception (four), and incontinence (three) were identified only with barium defecography. Nine (75%) subjects preferred FECOM to barium paste (p < 0.001) and reported that expulsion of this device mimicked more closely their stools at home (p < 0.05). CONCLUSION: The anorectal angle is influenced by the form and consistency of stool material and is lower with barium paste. The detection of rectocele, mucosal intussusception, and barium leakage in normal subjects during barium defecography questions the significance of these findings. FECOM appears to be a realistic alternative to barium paste for performing defecography.

Adult↗

PubMed1998

Is coffee a colonic stimulant?

BACKGROUND: It is unclear if ingestion of coffee affects colonic function and if this effect is due to its caffeine content. We investigated the effects of coffee on colonic motor activity in healthy humans. METHODS: We performed ambulatory colonic manometry by placing a six-sensor solid-state probe up to the mid-transverse colon in 12 healthy subjects. The following day, over a 10 h period, subjects received four stimuli: 240 ml of three drinks at 45 degrees C in random order: black Colombian coffee (150 mg caffeine), decaffeinated coffee or water and 1000 kcal meal. We analyzed the effects of each stimulant on colonic motor responses. RESULTS: Caffeinated coffee, decaffeinated coffee and meal induced more activity in the colon with a greater area under the curve of pressure waves (P < 0.01) and a greater number of propagated contractions (P < 0.05) when compared with water. Caffeinated coffee, decaffeinated coffee and meal induced greater (P < 0.05) motor activity in the transverse/descending colon when compared with the rectosigmoid colon. The effects of decaffeinated coffee on colonic motility were not significantly different from those of water or caffeinated coffee and were lower (P < 0.05) than that of a meal. CONCLUSION: Caffeinated coffee stimulates colonic motor activity. Its magnitude is similar to a meal, 60% stronger than water and 23% stronger than decaffeinated coffee.

Adult↗

PubMed1996

Periodic rectal motor activity: the intrinsic colonic gatekeeper?

BACKGROUND: Rectal motor activity is incompletely understood. The aim of this study was to characterize the patterns of rectal motor activity and to examine their diurnal variation and their relationships to proximal colonic activity and to meals. METHODS: We performed a 30-h ambulatory motility study by recording pressure activity at multiple sites in the colon in 18 normal subjects. RESULTS: During 288 h of recording, discrete bursts of tonic and phasic activity were seen in the rectum of all subjects at night and during the day lasting > or = 3 min, with a predominant frequency of 3 waves/min: periodic rectal motor activity (PRMA). Nocturnally, the number of cycles and the proportion of time occupied by this activity were greater (p < 0.001) and the inter-cycle interval was shorter (p < 0.008) compared with daytime, but the cycle duration was similar. Only 4 versus 5% (nocturnal vs daytime) of cycles propagated aborad, whereas 36 versus 14% (p < 0.01) propagated retrogradely, 16 versus 47% (p < 0.01) occurred simultaneously, and 44 versus 34% were confined to the rectum. There was considerable intra- and intersubject variability. PRMA was not related to meals or to anal motor activity, but 81% of nocturnal and 94% of daytime cycles occurred within 5 min of a motor event in the more proximal colon. CONCLUSIONS: PRMA is a characteristic feature of the normal rectum and is more frequent at night. The temporal association with motor events in the proximal colon suggests that PRMA is triggered by the arrival of stool or gas in the rectum. Because most cycles are either segmental or are propagated retrogradely, PRMA may serve as an intrinsic braking mechanism that prevents untimely flow of colonic contents, particularly during sleep.

Adult↗