Recommendations for the reopening and activity resumption of the neurogastroenterology units in the face of the COVID-19 pandemic. Position of the Sociedad Latinoamericana de Neurogastroenterología. / Recomendaciones para la reapertura y reinicio de actividades de las Unidades de Neurogastroenterología ante la pandemia por COVID-19. Posicionamiento de la Sociedad Latinoamericana de Neurogastroenterología.

The COVID-19 pandemic has forced the establishment of preventive measures against contagion during the performance of diagnostic and therapeutic tests in gastroenterology. Digestive tract motility tests involve an intermediate and elevated risk for the transmission of COVID-19 infection. Given their elective or non-urgent indication in the majority of cases, we recommend postponing those tests until significant control of the infection rate in each Latin American country has been achieved during the pandemic. When the health authorities allow the return to normality, and in the absence of an effective treatment for or preventive vaccine against COVID-19 infection, we recommend a strict protocol for classifying patients according to their infectious-contagious status through the appropriate use of tests for the detection of the virus and the immune response to it, and the following of protective measures by the healthcare personnel to prevent contagion during the performance of a gastrointestinal motility test.

El incremento del hidrógeno en el aire espirado no predice la intolerancia a la fibra en la dieta en el síndrome del intestino irritable con constipación: estudio piloto / Breath hydrogen levels do not predict fiber intolerance in irritable bowel syndrome with constipation

BACKGROUND: Irritable Bowel Syndrome (IBS) is characterized by the worsening of symptoms with a high fiber diet. This intolerance could be related to an increase in colonic bacterial fermentation. The hydrogen breath test (HBT) is a marker of the intestinal micro flora fermentative capacity. AIM: To assess if there is an association between hydrogen (H2) levels and clinical changes between diets with and without bran. PATIENTS AND METHODS: 10 women with predominantly constipated irritable bowel syndrome (Rome II criteria) received a lowfiber diet during one week. This phase was followed by a second 7 day period with the same diet but supplemented with 12 g of crude dietary fiber. At the end of both periods, patients completed a symptom scale (Lickert type) and performed a HBT. RESULTS: Comparing both periods with a different diet the median difference in the clinical scale score (-2.5) shows a tendency favorable to the diet without bran, p = 0.048. In the fiber period the median increase of 2 ppm in H2 values was not significant deferent. Neither was possible to establish an association between breath H2 and the clinical response to a fiber diet. CONCLUSIONS: In this pilot study we could not detect ary association between breath H2 levels and the clinical response to dietary fiber.

Introducción: Los pacientes con síndrome del intestino irritable (SII) frecuentemente agravan sus síntomas cuando incorporan fibra insoluble en su dieta. Esta intolerancia podría estar relacionada con una incrementada fermentación colónica. El nivel de hidrógeno en el aire espirado es una variable dependiente de la capacidad fermentativa del contenido bacteriano del intestino por lo que podría representar un recurso capaz de predecir el grado de intolerancia a la fibra dietética. Objetivo: El objetivo de este estudio piloto fue investigar si existe una asociación entre los niveles de hidrógeno (H2) en el aire espirado y la respuesta clínica a las dietas con y sin fibra. Pacientes y métodos: En este estudio piloto se incluyeron diez mujeres afectadas de síndrome de intestino irritable con constipación (Criterios Roma II). Siguieron una dieta poco fermentable durante 14 días. En la primera semana las pacientes se sujetaron a la dieta sin ningún agregado, en la segunda semana incorporaron 12 gr diarios de fibra dietaria cruda. Al finalizar ambos períodos las pacientes completaron una escala de Lickert de 7 ítems donde se valoró la respuesta clínica a la dieta administrada y se midió la excreción de H2 en el aire espirado. Resultados: Comparando ambas dietas, se observó que la mediana de las diferencias de los puntajes clínicos (-2,5) indicaba una tendencia favorable a la dieta poco fermentable sin fibra, p=0,048. El incremento de la mediana de la concentración de H2 en el aire espirado fue de 2 ppm para la dieta con fibra, pero el mismo no fue significativo. Tampoco se pudo demostrar una tendencia que permitiera relacionar los valores de H2 con la respuesta clínica a la fibra dietética. Conclusión: Los resultados de este estudio no lograron demostrar una asociación entre los niveles de hidrógeno en el aire espirado y la respuesta clínica a la dieta con fibra.

El incremento del hidrógeno en el aire espirado no predice la intolerancia a la fibra en la dieta en el síndrome del intestino irritable con constipación: estudio piloto / Breath hydrogen levels do not predict fiber intolerance in irritable bowel syndrome with constipation

BACKGROUND: Irritable Bowel Syndrome (IBS) is characterized by the worsening of symptoms with a high fiber diet. This intolerance could be related to an increase in colonic bacterial fermentation. The hydrogen breath test (HBT) is a marker of the intestinal micro flora fermentative capacity. AIM: To assess if there is an association between hydrogen (H2) levels and clinical changes between diets with and without bran. PATIENTS AND METHODS: 10 women with predominantly constipated irritable bowel syndrome (Rome II criteria) received a lowfiber diet during one week. This phase was followed by a second 7 day period with the same diet but supplemented with 12 g of crude dietary fiber. At the end of both periods, patients completed a symptom scale (Lickert type) and performed a HBT. RESULTS: Comparing both periods with a different diet the median difference in the clinical scale score (-2.5) shows a tendency favorable to the diet without bran, p = 0.048. In the fiber period the median increase of 2 ppm in H2 values was not significant deferent. Neither was possible to establish an association between breath H2 and the clinical response to a fiber diet. CONCLUSIONS: In this pilot study we could not detect ary association between breath H2 levels and the clinical response to dietary fiber.(AU)

Introducción: Los pacientes con síndrome del intestino irritable (SII) frecuentemente agravan sus síntomas cuando incorporan fibra insoluble en su dieta. Esta intolerancia podría estar relacionada con una incrementada fermentación colónica. El nivel de hidrógeno en el aire espirado es una variable dependiente de la capacidad fermentativa del contenido bacteriano del intestino por lo que podría representar un recurso capaz de predecir el grado de intolerancia a la fibra dietética. Objetivo: El objetivo de este estudio piloto fue investigar si existe una asociación entre los niveles de hidrógeno (H2) en el aire espirado y la respuesta clínica a las dietas con y sin fibra. Pacientes y métodos: En este estudio piloto se incluyeron diez mujeres afectadas de síndrome de intestino irritable con constipación (Criterios Roma II). Siguieron una dieta poco fermentable durante 14 días. En la primera semana las pacientes se sujetaron a la dieta sin ningún agregado, en la segunda semana incorporaron 12 gr diarios de fibra dietaria cruda. Al finalizar ambos períodos las pacientes completaron una escala de Lickert de 7 ítems donde se valoró la respuesta clínica a la dieta administrada y se midió la excreción de H2 en el aire espirado. Resultados: Comparando ambas dietas, se observó que la mediana de las diferencias de los puntajes clínicos (-2,5) indicaba una tendencia favorable a la dieta poco fermentable sin fibra, p=0,048. El incremento de la mediana de la concentración de H2 en el aire espirado fue de 2 ppm para la dieta con fibra, pero el mismo no fue significativo. Tampoco se pudo demostrar una tendencia que permitiera relacionar los valores de H2 con la respuesta clínica a la fibra dietética. Conclusión: Los resultados de este estudio no lograron demostrar una asociación entre los niveles de hidrógeno en el aire espirado y la respuesta clínica a la dieta con fibra.(AU)

[Gastric solitary plasmacytoma associated with +Helicobacter pylori infection]. / Plasmocitoma solitario gástrico asociado a infección por Helicobacter pylori.

Solitary gastric plasmacitomas are infrequent tumors. They account for 5% of the extramedullary plasmacitomas. We report an unusual case in a 14 years old boy. The patient has had gastric symptoms for 2 years prior to an endoscopic examination. A fungating, ulcerated lesion was observed in the antrum. The biopsies showed a monoclonal, Lambda positive, diffuse, plasmocitic proliferation infiltrating the mucosa. Also a moderate number of Helicobacter pylori were identified in the gastric pits and numerous lymphoid follicules were observed in the deep portion of the mucosa. In view of the presence of HP infection the patient was treated with Orneprazole and Clarithromycin. Endoscopic examination and biopsies performed 3 and 5 months later showed a complete remission of the gastric lesion. At the time of this report the patient is in good physical condition, has recovered his weight and has grown 5 cm. Differential diagnosis with plasmo limpho in chronic gastritis and with lympheicitic lymphoma with plasmocitoid features had to be done. The macroscopic appearance of the gastric lesion, the absence of other inflammatory cells and monoclonality of the plasmocitic infiltration ruled out chronic gastritis. The negative staining for CD 20 as well as the abscence of lymphoid cells in the mucosal infiltrate give support: to the diagnosis of plasmocitoma. The close association between gastric MALT lymphoma and HP infection has been reported as well as its regression after antibiotic treatment for its erradication. In our review of the literature we failed to find any references to the association of HP with gastric plasmocitoma nor to its regression after antibiotic therapy.

Colonic motility in man: features in normal subjects and in patients with chronic idiopathic constipation.

The human colon is still a relatively unknown viscus, especially concerning its motor activity. However, in recent years, techniques have been perfected that allow a better understanding of colonic motility, especially through prolonged recording periods. In this way, it has been demonstrated that the viscus contracts according to a circadian trend, is responsive to physiological stimuli (meals, sleep), and features high amplitude, propulsive contractions that are part of the complex dynamic of the defecatory process. These physiological properties and their alterations in patients with chronic idiopathic constipation are reviewed in this article.

Plasmocitoma solitario gástrico asociado a infección por Helicobacter pylori / Gastric solitary plasmacytoma associated to Helicobacter pylori infection

Los plasmocitomas solitarios gástricos son tumores infrecuentes y representan el 5 por ciento de los plasmocitomas extramoleculares. Estos presentan algunas características que los diferencian de los plasmocitomas óseos, independientemente de su localización, como son: una mayor sobrevida con terapia conservadora local, infrecuentes metástasis óseas y prolongadas remisiones. Estas condiciones de su evolución y algunas características histológicas han llevado a algunos autores a considerar un origen común con linfomas MALT de bajo grado. Al momento del diagnóstico la mayoría de los casos presenta invasión total o de la mayor parte de la pared gástrica. Los plasmocitomas pueden producir o no inmunoglobulinas y su tratamiento de elección es el quirúrgico. Presentamos un caso inusual de plasmocitoma extramedular, en un varón de 14 años, que solamente invadaría la mucosa gástrica, estaba a sociado a la presencia de Helicobacter Pilori y curó con el tratamiento indicado para su erradicación.

Plasmocitoma solitario gástrico asociado a infección por Helicobacter pylori / Gastric solitary plasmacytoma associated to Helicobacter pylori infection

Los plasmocitomas solitarios gástricos son tumores infrecuentes y representan el 5 por ciento de los plasmocitomas extramoleculares. Estos presentan algunas características que los diferencian de los plasmocitomas óseos, independientemente de su localización, como son: una mayor sobrevida con terapia conservadora local, infrecuentes metástasis óseas y prolongadas remisiones. Estas condiciones de su evolución y algunas características histológicas han llevado a algunos autores a considerar un origen común con linfomas MALT de bajo grado. Al momento del diagnóstico la mayoría de los casos presenta invasión total o de la mayor parte de la pared gástrica. Los plasmocitomas pueden producir o no inmunoglobulinas y su tratamiento de elección es el quirúrgico. Presentamos un caso inusual de plasmocitoma extramedular, en un varón de 14 años, que solamente invadaría la mucosa gástrica, estaba a sociado a la presencia de Helicobacter Pilori y curó con el tratamiento indicado para su erradicación. (AU)

Stimulation of inflammatory mediators secretion by chemotactic peptides in rat colitis model.

Colonic inflammation was produced in rats by chemotactic peptides acting on polymorphonuclear leucocytes. Instillation during one hour of formylated tripeptide: formylmethionyl-leucyl-phenylalanine (FMLP) and a tetrapeptide: alanine-glycine-sefine-glutamine (AGSG) into rat colon caused erosions and exulcerations. Neutrophils increased secondary to instillation, predominantly with FMLP, and mucus depletion was marked in the cecum. Chloride ion secretion and mucosal permeability were significatively greater in the colonic lumen with the chemotactic peptides. Histamine and serotonin concentration were greater in the colonic fluid in animals treated with the peptides. These observations could suggest that the presence of chemotactic peptides at the colonic lumen produce changes at the mucosal wall, that would participate in generation and perpetuation of the colonic inflammation.

Stimulation of inflammatory mediators secretion by chemotactic peptides in rat colitis model

Colonic inflammation was produced in rats by chemotactic peptides acting on polymorphonuclear leucocytes. Instillation during one hour of formylated tripeptide: formylmethionyl-leucy-phenylalanine (FMLP) and a tetrapeptide: alanine-glycine-sefine-glutamine (AGSG) into rat colon caused erosions and exulcerations. Neutrophils increased secondary to instillation, predominantly with FMLP, and mucus depletion was marked in the cecum. Chloride ion secretion and mucosal permeability were significatively greater in the colonic lumen with the chemotactic peptides. Histamine and serotonin concentration were greater in the colonic fluid in animals treated with the peptides. These observations could suggest that the presence of chemotactic peptides at the colonic lumen produce changes at the mucosal wall, that would participate in generation and perpetuation of the colonic inflammation.

Stimulation of inflammatory mediators secretion by chemotactic peptides in rat colitis model

Colonic inflammation was produced in rats by chemotactic peptides acting on polymorphonuclear leucocytes. Instillation during one hour of formylated tripeptide: formylmethionyl-leucy-phenylalanine (FMLP) and a tetrapeptide: alanine-glycine-sefine-glutamine (AGSG) into rat colon caused erosions and exulcerations. Neutrophils increased secondary to instillation, predominantly with FMLP, and mucus depletion was marked in the cecum. Chloride ion secretion and mucosal permeability were significatively greater in the colonic lumen with the chemotactic peptides. Histamine and serotonin concentration were greater in the colonic fluid in animals treated with the peptides. These observations could suggest that the presence of chemotactic peptides at the colonic lumen produce changes at the mucosal wall, that would participate in generation and perpetuation of the colonic inflammation. (AU)

Influence of pirenzepine on colonic serotonin changes induced by short chain fatty acid.

In this work we have demonstrated the influence of a short chain fatty acid (acetate) on the number of enterochromaffin (EC) cells containing serotonin (5HT), at two different pH (pH 6.9 absorptive stimuli, and pH 2.9 secretory stimuli), infused into the colon during one hour. The number of EC cells decrease significatively, specially in the cecum with a solution of low pH (2.9). The action of piprenzepine in preventing this reduction demonstrated that was partly mediated by a cholinergic receptor mechanism. On the other hand, a decrease on the release of 5HT to the lumen was a observed under the influence of pirenzepine. We conclude that the short chain fatty acid acetate, at a low pH induces the release of serotonin through a cholinergic mechanisms indicated by the inhibition observed with antimuscarinic drug.

[Do the physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?]. / Los caracteres físicos de los Marcadores Radiopacos modifican los resultados de la medición del tiempo de tránsito colónico?

UNLABELLED: This study was performed in 15 healthy control subjects (8 males- age 23-70 and 7 females age 20-74) as a way to compare the total and segmental colonic transit time with two different type of radiopaque markers. One type of markers was 3 mm cut sections of a radiopaque polietilene 14 French Levine tube, with a medium weight of 64.3 mg and a specific gravity (SG) of 1.28. The other type were 7 mm lenticular insoluble barium (lentils) with medium weight of 231 mg and a SG of 1.87. Each subject ingested 20 markers of each type with the breakfast and front and profile plain films of the abdomen were taken 24 and 48 hs after. The total colonic transit time for the polietilene markers was 17.7 hs and 27.3 hs for the barium type (BM) (p < 0.001). The segmental transit time for right colon was 2.4 hs (PM) and 9.7 hs (PM) and 9.7 hs (BM) (p < 0.001) in the left colon 9.5 hs (PM) and 11.3 hs (BM) and in rectoanun 5.9 hs (BM) with no statistical significance. CONCLUSION: the physical characteristics of the radiopaque markers can modify the results of the colonic transit times.

Influence of pirenzepine on colonic serotonin changes induced by short chaim fatty acid

En este trabajo hemos la influencia de un ácido graso de cadena corta (acetato) sobre el número de células enterocromafines (EC) conteniendo serotonina (5HT) a dos diferentes pH (pH 6.9, estímulo absortivo y pH 2.9 estímulo secretor) infundido durante una hora en el colon. El número de células EC disminuye significativament con una solución infundida a pH 2.9, especialmente en el ciego. La acción de la pirencepina en prevenir esta reducción demuestra que el mecanismo se efectúa parcialmente a través de receptores colinérgicos. Por parte, se observa una disminución de la liberación de 5HT, a través de un mecanismo colinérgico, como lo indica la inhibición observada con la droga antimuscarínica

Influence of pirenzepine on colonic serotonin changes induced by short chaim fatty acid

En este trabajo hemos la influencia de un ácido graso de cadena corta (acetato) sobre el número de células enterocromafines (EC) conteniendo serotonina (5HT) a dos diferentes pH (pH 6.9, estímulo absortivo y pH 2.9 estímulo secretor) infundido durante una hora en el colon. El número de células EC disminuye significativament con una solución infundida a pH 2.9, especialmente en el ciego. La acción de la pirencepina en prevenir esta reducción demuestra que el mecanismo se efectúa parcialmente a través de receptores colinérgicos. Por parte, se observa una disminución de la liberación de 5HT, a través de un mecanismo colinérgico, como lo indica la inhibición observada con la droga antimuscarínica (AU)

Los caracteres físicos de los Marcadores Radiopacos modifican los resultados de la medición del tiempo de tránsito colónico? / [Do the physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?]

This study was performed in 15 healthy control subjects (8 males- age 23-70 and 7 females age 20-74) as a way to compare the total and segmental colonic transit time with two different type of radiopaque markers. One type of markers was 3 mm cut sections of a radiopaque polietilene 14 French Levine tube, with a medium weight of 64.3 mg and a specific gravity (SG) of 1.28. The other type were 7 mm lenticular insoluble barium (lentils) with medium weight of 231 mg and a SG of 1.87. Each subject ingested 20 markers of each type with the breakfast and front and profile plain films of the abdomen were taken 24 and 48 hs after. The total colonic transit time for the polietilene markers was 17.7 hs and 27.3 hs for the barium type (BM) (p < 0.001). The segmental transit time for right colon was 2.4 hs (PM) and 9.7 hs (PM) and 9.7 hs (BM) (p < 0.001) in the left colon 9.5 hs (PM) and 11.3 hs (BM) and in rectoanun 5.9 hs (BM) with no statistical significance. Conclusion: the physical characteristics of the radiopaque markers can modify the results of the colonic transit times.

Los caracteres fisicos de los marcadores radiopacos modifican los resultados de la medicion del tiempo de transito colonico? / The physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?

El objetivo de este trabajo es comparar en sujetos controles sanos el tiempo de tránsito colónico total y segmentario con dos tipos de marcadores radiopacos utilizados en nuestro medio. Se estudiaron 16 personas sanas, 8 varones de 23 a 70 años de edad y 7 mujeres de 20 a 74 años con dieta habitual. Un tipo de marcadores corresponde a cilindros huecos de 3 mm de longitud onbtenidos de sondas de Levine 14 French con un peso medio de 64.3 mg y una gravedad específica (GE) de 1.28, el otro tipo de marcadores corresponde a grageas lenticulares indisolubles de bario, de 7 mm de diámetro, 231 mg de peso y GE específica de 1.87. Cada individuo ingirió luego del desayuno 20 marcadores de cada tipo y se obtuvieron radiografías simples de abdomen en decúbito dorsal y lateral izquierdo de pelvis a las 24 hs y 48 hs. El tiempo de tránsito colónico total para marcadores de polietileno fue de 17.7 hs. y para los de bario 27.3 hs. (p < 0.001). En el colon derecho fue respectivamente de 2,4 y 9,7 hs. (p < 0.001) en el izquierdo de 9,5 y 11,3 y en el recto ano de 5,9 y 6,3 (sin significancia estadística). Concluimos que los caracteres físicos de los marcadores radioopacos modifican los resultados del tiempo de tránsito colónico

Los caracteres físicos de los Marcadores Radiopacos modifican los resultados de la medición del tiempo de tránsito colónico? / [Do the physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?]

This study was performed in 15 healthy control subjects (8 males- age 23-70 and 7 females age 20-74) as a way to compare the total and segmental colonic transit time with two different type of radiopaque markers. One type of markers was 3 mm cut sections of a radiopaque polietilene 14 French Levine tube, with a medium weight of 64.3 mg and a specific gravity (SG) of 1.28. The other type were 7 mm lenticular insoluble barium (lentils) with medium weight of 231 mg and a SG of 1.87. Each subject ingested 20 markers of each type with the breakfast and front and profile plain films of the abdomen were taken 24 and 48 hs after. The total colonic transit time for the polietilene markers was 17.7 hs and 27.3 hs for the barium type (BM) (p < 0.001). The segmental transit time for right colon was 2.4 hs (PM) and 9.7 hs (PM) and 9.7 hs (BM) (p < 0.001) in the left colon 9.5 hs (PM) and 11.3 hs (BM) and in rectoanun 5.9 hs (BM) with no statistical significance. Conclusion: the physical characteristics of the radiopaque markers can modify the results of the colonic transit times.

Influence of pirenzepine on colonic serotonin changes induced by short chain fatty acid.

In this work we have demonstrated the influence of a short chain fatty acid (acetate) on the number of enterochromaffin (EC) cells containing serotonin (5HT), at two different pH (pH 6.9 absorptive stimuli, and pH 2.9 secretory stimuli), infused into the colon during one hour. The number of EC cells decrease significatively, specially in the cecum with a solution of low pH (2.9). The action of piprenzepine in preventing this reduction demonstrated that was partly mediated by a cholinergic receptor mechanism. On the other hand, a decrease on the release of 5HT to the lumen was a observed under the influence of pirenzepine. We conclude that the short chain fatty acid acetate, at a low pH induces the release of serotonin through a cholinergic mechanisms indicated by the inhibition observed with antimuscarinic drug.

Los caracteres fisicos de los marcadores radiopacos modifican los resultados de la medicion del tiempo de transito colonico? / The physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?

El objetivo de este trabajo es comparar en sujetos controles sanos el tiempo de tránsito colónico total y segmentario con dos tipos de marcadores radiopacos utilizados en nuestro medio. Se estudiaron 16 personas sanas, 8 varones de 23 a 70 años de edad y 7 mujeres de 20 a 74 años con dieta habitual. Un tipo de marcadores corresponde a cilindros huecos de 3 mm de longitud onbtenidos de sondas de Levine 14 French con un peso medio de 64.3 mg y una gravedad específica (GE) de 1.28, el otro tipo de marcadores corresponde a grageas lenticulares indisolubles de bario, de 7 mm de diámetro, 231 mg de peso y GE específica de 1.87. Cada individuo ingirió luego del desayuno 20 marcadores de cada tipo y se obtuvieron radiografías simples de abdomen en decúbito dorsal y lateral izquierdo de pelvis a las 24 hs y 48 hs. El tiempo de tránsito colónico total para marcadores de polietileno fue de 17.7 hs. y para los de bario 27.3 hs. (p < 0.001). En el colon derecho fue respectivamente de 2,4 y 9,7 hs. (p < 0.001) en el izquierdo de 9,5 y 11,3 y en el recto ano de 5,9 y 6,3 (sin significancia estadística). Concluimos que los caracteres físicos de los marcadores radioopacos modifican los resultados del tiempo de tránsito colónico (AU)

Action of cisapride on rat colonic secretion.

The stimulating effect of cisapride on the motility of the digestive tract is well known. However, there are only a few studies on the influence of this drug on the absorptive or secretory activity of the colonic mucosa. In the present study, the ability of cisapride to alter the mural transport of water and electrolytes in the colon and its effects on mucus secretion and albumin permeation were studied. The effects of cisapride on the rat colon in vivo were studied under different conditions, by means of an instillation of sodium acetate solution at pH 6.9, which induced absorption of water and electrolytes, and in two models of colonic secretion, one employing the instillation of an acetic acid solution at pH 2.9 and the other, an intravenous infusion of 5-hydroxytryptamine (serotonin) 45 micrograms.kg-1.min-1 together with intracolonic instillation of sodium acetate. Cisapride (i.v.), at a dose of 0.32 mg.kg-1, in rats whose colon was instilled with sodium acetate (pH 6.9) induced an increase in sodium absorption and a reduction in water absorption. Cisapride (i.v.), at doses of 0.32, 0.64 and 1.0 mg.kg-1, inhibited the secretion of water, Na+, Cl-, and mucus and the permeation of albumin induced by acetic acid instillation or by serotonin infusion. It is concluded that the effect of cisapride on the colonic mucosa varies in accordance with the functional mucosal conditions and that this action may be of clinical importance.