Colonic motility: practice or research?

Day-to-day reproducibility of prolonged ambulatory colonic manometry in healthy subjects

BACKGROUND

Although colonic manometry provides useful information regarding colonic physiology, considerable variability has been reported both for regional motility and manometric patterns. Whether colonic manometry is reproducible is not known.

METHODS

Seven healthy volunteers (three men, four women, mean age = 34 years) underwent two studies of 24-h ambulatory colonic manometry, each 2 weeks apart. Manometry was performed by placing a six-sensor solid-state probe, up to the hepatic flexure and anchored to colonic mucosa. Colonic motility was assessed by the number and area-under-curve (AUC) of pressure waves and motility patterns such as high-amplitude propagating contractions (HAPC). Waking and meal-induced gastrocolonic responses were also assessed. Paired t-test was used to examine the reproducibility and intra and interindividual variability.

KEY RESULTS

The number of pressure waves and propagating pressure waves and HAPC, and AUC were similar between the two studies. Diurnal variation, waking and meal-induced gastrocolonic responses were also reproducible. There was some variability in the incidence of individual colonic motor patterns.

CONCLUSIONS & INFERENCES

Colonic manometry findings were generally reproducible, particularly for the assessment of key physiologic changes, such as meal-induced gastrocolonic, HAPC, and waking responses.

Non-invasive measurement of pan-colonic pressure over a whole digestive cycle: Clinical applications of a capsule-style manometric system

AIM: To study the prolonged colonic motility under normal conditions with a novel capsule-style micro-system and to assess its clinical significance.

METHODS: A single use telemetry capsule (10 mm in diameter, 20 mm in length) embedded with a pressure sensor was ingested by the subjects. The sensor is capable of transmitting colonic pressure wirelessly for more than 130 h. The time of capsule entering the segmental colon was detected by ultrasound. The ultrasonic electrodes were mounted on the surface of the ileocecum and navel and at the junction of the left and rectosigmoid colon of the subjects in sequence, which were identified by abdominal X-rays with radiopaque markers. To verify the accuracy and reliability of ultrasonic detection of telemetry capsules at key points of colon, the segmental colonic transit time was simultaneously recorded by using radiopaque markers.

RESULTS: The signal lamp showed that all recorders could receive the radio signal transmitted by the telemetry capsule. The X-rays showed that all telemetry capsules were detected successfully when they were passing through the key points of colon. There was a significant correlation between the transit results obtained by ultrasonic detection or by radiopaque markers. Colorectal recording was obtained from 20 healthy subjects during 613 h (411 h during waking, 202 h during sleep). Compared to waking, the number of pressure contractions and the area under pressure contractions were significantly (P < 0.05) decreased during sleep (21 ± 5 h^-1vs 15 ± 4 h^-1, 463 ± 54 mmHg·s/min vs 342 ± 45 mmHg·s/min). The colonic motility exhibited significant regional variations both in the circadian behavior and in response to waking and meal.

CONCLUSION: The capsule-style micro-system is reliable and noninvasive, and may represent a useful tool for the study of physiology and pathology of colonic motor disorders.

Manometric techniques for the evaluation of colonic motor activity: current status

Colonic motility disorders are common conditions. However, our understanding of normal, and, consequently, pathological motor function of the colon remains limited, mainly due to the relative inaccessibility of this organ for study. Investigation of colonic motility may encompass one or more of the four separate components (myoelectric activity, phasic and tonic contractile activity and movement of intraluminal content) using electrophysiological, manometric or transit studies. Although transit studies provide the best 'functional' appreciation of colonic motor activity, and are the only techniques used in contemporary clinical practice, manometric methods are becoming increasingly popular, as they allow a direct study of colonic contractile activity over prolonged periods. To date, the majority of studies have been limited to the pelvic colon by a retrograde (per rectal) approach; however, recent technological advances have facilitated 'pan-colonic' investigation. This review concentrates on manometry of the human colon proximal to the sigmoid, and includes evaluation of both phasic and tonic motor activity, by utilization of perfused-tube and solid-state manometric catheters, and also the electronic barostat. Methodological techniques, experimental protocols and the analysis and interpretation of recorded data are critically explored, and a contemporary classification of colonic contractile activities is presented.

Ambulatory 24-h colonic manometry in healthy humans

Our aim was to investigate motor activity of the healthy, relatively unprepared colon in the ambulatory state. Twenty-five age- and gender-matched adults had a six-sensor solid-state probe inserted into the proximal transverse colon without sedation. Subjects ambulated freely and ate standard meals. In 528 h of recording, we found a lower (P < 0.05) area under the curve during the night. Waking induced a threefold increase in motility, whereas meals induced a twofold increase. Women showed less activity (P < 0.05) in the transverse/descending colon than men. The transverse/descending colon showed more (P < 0.05) activity than the rectosigmoid colon. Seven patterns were recognized; predominantly, they were simultaneous, propagated, or periodic bursts of 3-cycles/min (cpm) waves. A specialized propagating pressure wave with a high amplitude (>105 mmHg) and a prolonged duration (>14 s) occurred in all subjects (mean 10/day), mostly after waking, after meals, or with defecation. A 3-cpm motor activity was seen in the rectosigmoid region predominantly at night. The colon exhibits a wide spectrum of pressure activity around the clock, with gender and regional differences and circadian rhythm. This comprehensive study provides qualitative and quantitative normative data for colonic manometry.

Effects of fat and carbohydrate meals on colonic motor response

BACKGROUND

Ingestion of a meal stimulates colonic motility. It is unclear whether the nutrient composition of a meal affects colonic motor response.

AIMS

To investigate and compare the effects of a predominantly fat or carbohydrate meal on colonic motility.

METHODS

In 18 healthy subjects, ambulatory colonic manometry was performed by placing a six sensor, solid state probe from the mid-transverse colon to the rectum. In a randomised, crossover design, 10 and 27 hours after probe placement, subjects received 4.18 MJ meals containing 60% calories from fat or carbohydrate sources. Preprandial and postprandial pressure activity and motor patterns were evaluated.

RESULTS

Both meals induced phasic activity with a greater area under the curve (p<0.03) in the first postprandial hour, compared with the control period. Fat induced motor activity persisted longer (p<0.05) than that of the carbohydrate meal, but the onset of motor response was slower (p<0.001). Although both meals induced more (p<0.001) propagating pressure waves, only the fat meal induced more (p<0.05) simultaneous and retrograde waves. After both meals, 50% of subjects exhibited high amplitude (more than 103 mm Hg), prolonged duration (more than 13 seconds) propagating waves. Both meals induced greater activity (p<0.05) in the transverse/descending colon than in the rectosigmoid colon.

CONCLUSIONS

Carbohydrate meals induce colonic motor response, but the effects are short lived when compared with fat meals. The prolonged, segmental, and retrograde phasic activity induced by the fat meal may delay colon transit. Thus meal composition influences colonic motor response.

Intestinal motility

This review covers the recent advances that have been made in intestinal motility. Failure to stimulate the cephalic response when enteral tube feeding via the nasogastric route is important in contributing to enteral tube feeding related diarrhoea, which cannot be initially overcome by the use of fibre containing feeds. Dysfunction of the nervous system and visceral hypersensitivity appear to be important in contributing to the symptoms associated with irritable bowel syndrome.

Inflammatory bowel disease and smoking--a review

The relationship between smoking and inflammatory bowel disease is a curious but well-established one. It is negatively associated with ulcerative colitis but positively associated with Crohn's disease. It also has opposite influences on the clinical course of the two conditions with possible beneficial effect in ulcerative colitis and detrimental effect in Crohn's disease. The diametrically "opposite" relationship of smoking status with the two conditions has been the subject of much interest in the hope that it may reveal pathogenic mechanisms responsible for the two conditions and possibly offer the key to alternative therapeutic options. Nicotine may be the principal agent in smoking responsible for the association; trials have shown it to be of some benefit in ulcerative colitis, but further research is required to establish its therapeutic role and possible mechanisms of action. In this article, we review the historical, clinical, and therapeutic aspects of the association between smoking and inflammatory bowel disease.