Acute transcutaneous electrical stimulation (TES) augments esophageal contractility in patients with weak peristalsis.

BACKGROUND: Lung transplantation (LTx) remains controversial in patients with absent peristalsis (AP) given the increased risk for gastroesophageal reflux (GER), and chronic lung allograft dysfunction. Furthermore, specific treatments to facilitate LTx in those with AP have not been widely described. Transcutaneous Electrical Stimulation (TES) has been reported to improve foregut contractility in LTx patients and therefore we hypothesize that TES may augment the esophageal motility of patients with ineffective esophageal motility (IEM). METHODS: We included 49 patients, 14 with IEM, 5 with AP, and 30 with normal motility. All subjects underwent standard high-resolution manometry and intraluminal impedance (HRIM) with additional swallows as TES was delivered. RESULTS: TES induced a universal impedance change observable in real-time by a characteristic spike activity. TES significantly augmented the contractile vigor of the esophagus measured by the distal contractile integral (DCI) in patients with IEM [median DCI (IQR) 0 (238) mmHg-cm-s off TES vs. 333 (858) mmHg-cm-s on TES; p = .01] and normal peristalsis [median DCI (IQR) 1545 (1840) mmHg-cm-s off TES vs. 2109 (2082) mmHg-cm-s on TES; p = .01]. Interestingly, TES induced measurable contractile activity (DCI > 100 mmHg-cm-s) in three out of five patients with AP [median DCI (IQR) 0 (0) mmHg-cm-s off TES vs. 0 (182) mmHg-cm-s on TES; p < .001]. CONCLUSION: TES acutely augmented contractile vigor in patients with normal and weak/ AP. The use of TES may positively impact LTx candidacy, and outcomes for patients with IEM/AP. Nevertheless, further studies are needed to determine the long-term effects of TES in this patient population.

Safety and Efficacy of Intermittent Colonic Exoperistalsis Device to Treat Chronic Constipation: A Prospective Multicentric Clinical Trial.

INTRODUCTION: Chronic constipation is associated with various comorbidities and reduced quality of life. Current solutions, either pharmacological or invasive, show limited efficacy. Manual colon-specific massage is a well-established intervention to treat chronic constipation, but it should be applied daily. MOWOOT automatically provides intermittent colonic exo-peristalsis (ICE) treatment like that in manual massage. METHODS: This study assessed the safety and effectiveness of the ICE device to treat chronic constipation due to neurogenic bowel dysfunction or idiopathic causes with high component of pelvic floor disorders. The ICE device was used daily for 20 minutes over 4 weeks. Each participant was followed for 9 consecutive weeks. The same outcome measures (primary: complete bowel movements per week; secondary: Knowles Eccersley Scott Symptom Score and Patient Assessment of Constipation Quality of Life among others) were assessed at baseline (V1), last intervention weeks (V2), and post-treatment (V3). Responders were defined for selected outcomes as better results at V2 respect to V1. RESULTS: N = 92 adult patients constituted the intention-to-treat population, with N = 65 as the per protocol population. Adherence (quantity of treatment received) was ≥95% in the intention-to-treat population. Adverse events related with the treatment were low (8.7%). Using the device significantly increased the number of complete bowel movements per week (V2 - V1 = 1.8 [2.7], P < 0.0001), reduced the symptoms of chronic constipation (Knowles Eccersley Scott Symptom Score V2 - V1 = -3.9 [5.0], P < 0.0001), improved quality of life (Patient Assessment of Constipation Quality of Life V2 - V1 = -0.7 [0.8], P < 0.0001), and facilitated a reduction in laxatives. Colon transit and fecal consistency were not modified. There was a high number of responders (>70%). DISCUSSION: Considering safety, adherence, and efficacy being demonstrated, the results favor the use of MOWOOT to treat chronic constipation (Visual abstract, Supplementary Digital Content 1, http://links.lww.com/CTG/A440).(Equation is included in full-text article.).

Short-term outcomes of Chait Trapdoor for antegrade continence enema in adults.

OBJECTIVE: To examine our short-term experience of antegrade continence enema (ACE) delivered via a Chait Trapdoor (Cook Medical, Bloomington, IN) in adults with intractable neurogenic bowel. METHODS: We performed a retrospective review at the Universities of Utah and Minnesota of 15 patients with Chait Trapdoor placed for the purpose of ACE from 2011 to 2013. Our primary outcome was continued utilization of the Chait Trapdoor. Secondary outcomes included volume of ACE used and time to produce a bowel movement. RESULTS: All patients had neurogenic bowel refractory to conventional bowel regimen. Mean follow-up was 6 months (range, 1-17 months). Thirteen patients had the Chait Trapdoor placed in the splenic flexure and 2 had it placed in the cecum. Of the 15 patients, 12 (80%) were still using the Chait Trapdoor at last follow-up. A median of 425 mL (range, 120-1000 mL) of fluid was used to produce a bowel movement in 5-120 minutes. Two patients developed postoperative wound infections, requiring return to the operating room (Clavien IIIb). Long-term complications included 5 patients with a dislodged tube requiring replacement by interventional radiology and 2 patients with local cellulitis. Two patients had the Chait Trapdoor moved to a new location to improve efficacy. CONCLUSION: Although the revision, removal, and complication rates were high, 80% of the patients were satisfied with the function and continued to use the Chait Trapdoor. The volume of irrigation required for ACE and the time it takes to produce a bowel movement vary significantly between patients.

Botulinum toxin injection in dysphagia syndromes with preserved esophageal peristalsis and incomplete lower esophageal sphincter relaxation.

BACKGROUND: Botulinum toxin injection into the lower esophageal sphincter (LES) treats dysphagia syndromes with preserved peristalsis and incomplete LES relaxation (LESR). We evaluated clinical and esophageal motor characteristics predicting response, and compared duration of efficacy to similarly treated achalasia patients. METHODS: Thirty-six subjects (59 ± 2.2 years, 19F/17M) with incomplete LESR on high resolution manometry (HRM) treated with botulinum toxin injection were identified. Individual and composite symptom indices were calculated, and HRM characteristics extracted. Symptom resolution for 6 months was a primary outcome measure, and repeat botulinum toxin injection, dysphagia recurrence or employment of alternate therapeutic approaches were secondary outcome measures. Duration of response was compared using Kaplan-Meier survival curves to a historical cohort of similarly treated achalasia subjects. KEY RESULTS: Response lasted a mean of 12.8 ± 2.3 months. Symptom relief for >6 months was seen in 58.3%; short (<6 months) response was associated with younger age, higher chest pain index, and esophageal body spastic features (P ≤ 0.04). On multivariate logistic regression, chest pain, younger age and contraction amplitudes >180 mmHg independently predicted <6 months relief (P < 0.05 for each). On survival analysis, relief with a single injection extended to 1 year in 54.8% and 1.5 years in 49.8%, statistically equivalent to that reported by 42 similarly treated achalasia subjects (59 ± 3.2 years, 24F/18M). Symptom relief was more prolonged compared to achalasia when repeat injections were performed on demand (P = 0.003). CONCLUSIONS & INFERENCES: Botulinum toxin injections can provide lasting symptom relief in dysphagia syndromes with incomplete LESR. Prominent perceptive symptoms and non-specific spastic features may predict shorter relief.

Time-resolved MRI after ingestion of liquids reveals motility changes after laparoscopic sleeve gastrectomy--preliminary results.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is generally considered a restrictive procedure. However, studies with nuclear medicine techniques have demonstrated that gastric motility changes occur following LSG. These motility changes could represent complementary mechanisms of weight loss. Therefore, we analyzed the stomach motility before and after LSG by means of dynamic MRI. METHODS: In this prospective pilot study, five female patients with a mean BMI of 51.6 kg/m(2) underwent MRI 1 day before LSG and 6 days and 6 months after LSG. Dynamic steady-state free precession sequences were used to analyze the gastric motility after ingestion of 500 ml water with a temporal resolution of 0.86 s. Axial image stacks were also repeatedly acquired to determine the intragastric fluid volume over time. RESULTS: Mean excess body mass index loss was 60.6% after 6 months. Dynamic analysis showed that antral propulsive peristalsis was preserved immediately after surgery and during follow-up, but fold speed increased significantly from 2.7 mm/s before LSG to 4.4 mm/s after 6 months. The sleeve itself remained without recognizable peristalsis in three patients and showed only uncoordinated or passive motion in two patients. Consequently, the fluid transport through the sleeve was markedly delayed, whereas the antrum showed accelerated propulsion with the emptying half-time decreasing from 16.5 min preoperatively to 7.9 min 6 months after surgery. CONCLUSIONS: Owing to the LSG procedure, the stomach is functionally divided into a sleeve without propulsive peristalsis and an accelerated antrum. Accelerated emptying seems to be caused by faster peristaltic folds.

Assessment of gastrointestinal propulsive activity using three different models of peristalsis in vivo in the mouse.

The protocols described in this unit are designed to assess the acute effects of drugs on the propulsive activity of the gastrointestinal muscles in the conscious mouse. These protocols are currently applied to investigate the pharmacological activity of novel compounds undergoing preclinical development and to obtain predictive data needed to advance drugs into clinical trials. Moreover, these methods could be useful in evaluating the functional toxicity by environmental or alimentary pollutants, like xenobiotics and naturally occurring toxins endowed with noxious activity in the control of physiologic peristalsis. The three models detailed-the measurement of gastric emptying, ileal transit, and colonic propulsion-are substantially non-invasive and do not require analgesic pretreatments or the induction of general anesthesia. In contrast to an in vitro approach, these in vivo studies provide a unified understanding of drug effects on gut functionality, in particular when the central nervous system, the extrinsic nerves, or the (neuro)endocrine system is targeted by the test drugs.

[Electric stimulation in dysphagia therapy--a review]. / Elektrische Stimulation in der Dysphagietherapie - Eine Ubersicht.

In the last years an increased interest in the electrical stimulation has consisted in the treatment of dysphagia. In the article we introduce the anatomical and physiological premises for the method. In a critical analysis the present state of art is represented, the clinical results are checked and the chances for the future are examined.

The effects of butyrate enemas on visceral perception in healthy volunteers.

Fermentation of dietary fibres by colonic microbes leads to the production of short chain fatty acids (mainly propionate, butyrate and acetate), which are utilized by the colonic mucosa. Previous studies showed positive effects of butyrate on parameters of oxidative stress, inflammation and apoptosis. Recent studies in rats, however, showed that butyrate increased visceral sensitivity. The aim of this study was to determine the effects of physiologically relevant concentrations of butyrate on visceral perception in healthy human subjects. Eleven healthy volunteers participated in this randomized double-blind, placebo controlled cross-over study. The study consisted of three periods of 1 week each, in which the volunteers daily self-administered rectal enemas containing 100, 50 mmol L(-1) butyrate, or placebo (saline) prior to sleeping. A rectal barostat measurement was performed at the start and the end of each test period for the measurement of pain, urge and discomfort. Butyrate treatment resulted in a dose-dependent reduction of pain, urge and discomfort throughout the entire pressure range of the protocol. At a pressure of 4 mmHg, 50 and 100 mmol L(-1) butyrate concentrations resulted in a 23.9% and 42.1% reduction of pain scores, respectively, and the discomfort scores decreased by 44.2% and 69.0% respectively. At a pressure of 67 mmHg, 50 and 100 mmol L(-1) of butyrate decreased the pain scores by 23.8% and 42%, respectively, and discomfort scores 1.9% and 5.2% respectively. Colonic administration of butyrate, at physiologically relevant concentrations, dose-dependently decreases visceral sensitivity in healthy volunteers.

Antispasmodic effect of hydroalcoholic extract of Thymus vulgaris on the guinea-pig ileum.

The effects of Thymus vulgaris hydroalcoholic extract on the contractile responses of the isolated guinea-pig ileum were investigated. Contraction changes in the terminal ileum of guinea pigs were monitored using a force displacement transducer amplifier connected to a physiograph. Thymus vulgaris extract inhibited the contractile responses in a dose-dependent manner and also decreased the amplitude of peristaltic waves. It is concluded that T. vulgaris has an antispasmodic action on guinea pig ileum by decreasing the amplitudes of the muscle contractions during peristalsis. The EC50 was calculated as 1.7 mg mL(-1). In guinea-pig ileum the extract led to an antispasmodic effect, possibly by affecting the anticholinergic and serotoninergic pathways.

[Ureter drugs]. / Les médicaments de l'uretère.

Many improvements have been made recently in the field of the ureteral smooth muscle pharmacology. After a brief summary on physiological basis, we review what is known about effects on ureter of different drugs class. In a second part, we review clinical applications for renal colic analgesia, calculi expulsive medical therapy, ESWL adjuvant treatment and preoperative treatment before retrograde access. There are now sufficient data on NSAID and alpha-blockers. beta-agonists, especially for beta3 selective ones, and topical drugs before retrograde access are interesting and should be further evaluated.

Is total colectomy the right choice in intractable slow-transit constipation?

BACKGROUND: The aim of the study was to evaluate the functional results of surgical treatment for intractable slow-transit constipation and to establish that the importance of correct diagnosis and type of colon resection (total or segmental) is essential to achieve optimal outcome while minimizing side effects. METHODS: Between 1995 and 2004, of the 450 patients presenting with chronic constipation, we further investigated 33 patients with a diagnosis of slow-transit constipation that had not improved with medical or rehabilitative treatment. Preoperative evaluation included a daily evacuation diary compiled using Wexner score, psychologic assessment, Medical Outcomes Study 36-item Short Form Health Survey (SF-36), radiologic investigation of colonic transit time, enema radiograph, colpo-cysto-defecography, anal manometry, and, in selected patients, colonoscopy and pudendal nerve terminal motor latency. In 15 cases, the cause of constipation was colonic slow-transit (with a mean Wexner score of 22), which was always associated with dolichocolon. The other 18 patients presented outlet obstruction, and, therefore, these results are not included in the present report. The 15 patients with slow-transit constipation were submitted to total laparoscopic colectomy (2), total open colectomy (6), and left laparoscopic hemicolectomy for left colonic slow-transit (7). RESULTS: Mean follow-up was 38 months. All patients except 1 presented improvement in symptoms with daily evacuations (P < .01; mean Wexner score, 6). Furthermore, results of the SF-36 test showed an improvement in the perception of physical pain, and the emotional, psychologic, and general health spheres after surgical treatment. CONCLUSIONS: Meticulous preoperative evaluation of intractable slow-transit constipation may discriminate between the different causes of chronic constipation and thus avoid the well-known "Iceberg syndrome," which is responsible for many treatment failures.

A comparative study of the effects of electroacupuncture and moxibustion in the gastrointestinal motility of the rat.

We compared the outcomes of the stimulation of specific sets of acupoints with either acupuncture or moxibustion over peristalsis. Twenty-five plastic beads were orally administered in the stomach of the rats and 90 min later animals were sacrificed, the stomach and small intestine were opened, and the number of beads remaining in each segment was counted. Forty rats were immobilized for 20 min and stimulated at either abdominal or hindlimbs acupoints, with either electroacupuncture or moxibustion. Under this restraint (stress) condition electroacupuncture at hindlimb points or moxibustion at abdominal points significantly enhanced gastric emptying (P < 0.02) as well as intestinal motility compared with animals subjected only to immobilization and not stimulated with electroacupuncture or moxibustion. We conclude that the effects of different acupoints and modes of stimulation (electrical vs. moxibustion) over gastrointestinal motility in rats subjected to restraint-induced stress is not uniform and discuss the different neural pathways underlying these differences.

Treatment with hypnotherapy reduces the sensory and motor component of the gastrocolonic response in irritable bowel syndrome.

OBJECTIVE: Postprandial symptoms in irritable bowel syndrome are common and relate to an exaggerated motor and sensory component of the gastrocolonic response. We investigated whether this response can be affected by hypnotherapy. METHODS: We included 28 patients with irritable bowel syndrome refractory to other treatments. They were randomized to receive gut-directed hypnotherapy 1 hour per week for 12 weeks (N = 14) or were provided with supportive therapy (control group; N = 14). Before randomization and after 3 months, all patients underwent a colonic distension trial before and after a 1-hour duodenal lipid infusion. Colonic sensory thresholds and tonic and phasic motor activity were assessed. RESULTS: Before randomization, reduced thresholds after vs. before lipid infusion were seen in both groups for all studied sensations. At 3 months, the colonic sensitivity before duodenal lipids did not differ between groups. Controls reduced their thresholds after duodenal lipids for gas (22 +/- 1.7 mm Hg vs. 16 +/- 1.6 mm Hg, p <.01), discomfort (29 +/- 2.9 mm Hg vs. 22 +/- 2.6 mm Hg, p <.01), and pain (33 +/- 2.7 mm Hg vs. 26 +/- 3.3 mm Hg, p <.01), whereas the hypnotherapy group reduced their thresholds after lipids only for pain (35 +/- 4.0 mm Hg vs. 29 +/- 4.7 mm Hg, p <.01). The colonic balloon volumes and tone response at randomization were similar in both groups. At 3 months, baseline balloon volumes were lower in the hypnotherapy group than in controls (83 +/- 14 ml vs. 141 +/- 15 ml, p <.01). In the control group, reduced balloon volumes during lipid infusion were seen (141 +/- 15 ml vs. 111 +/- 19 ml, p <.05), but not after hypnotherapy (83 +/- 14 ml vs. 80 +/- 16 ml, p >.20). CONCLUSION: Hypnotherapy reduces the sensory and motor component of the gastrocolonic response in patients with irritable bowel syndrome. These effects may be involved in the clinical efficacy of hypnotherapy in IBS.

Neural regulation of tone in the oesophageal body: in vivo barostat assessment of volume-pressure relationships in the feline oesophagus.

Recent combined manometric-barostat studies demonstrated that the oesophageal body exhibits both peristaltic contractions and tone. This study further characterized the neural modulation of tone in the feline oesophageal body. Simultaneous oesophageal barostat and manometry were performed in 20 adult cats under ketamine sedation. Oesophageal tone and peristalsis were assessed in the distal smooth muscle oesophagus. Cholinergic modulation was studied using neostigmine, erythromycin, atropine and vagotomy. Nitrergic regulation was assessed using sildenafil to increase cellular cyclic guanosine monophosphate and the nitric oxide synthase blocker Nomega-nitro-l-arginine (l-NNA). The presence of a tonic contractile activity in the distal oesophageal body was confirmed. Peristaltic contractions proceeded along the oesophageal body over the background tonic contraction. Neostigmine and erythromycin enhanced (20-30%) whereas bilateral vagotomy and atropine strongly decreased oesophageal tone (50-60%). However, l-NNA increased (40%) and sildenafil decreased oesophageal tone (30%). Therefore, tonic contractile activity in the oesophageal body is mainly caused by a continuous cholinergic excitatory input. A nitric oxide inhibitory mechanism may have a complementary role in the regulation of oesophageal tone.

Appearance of peristaltic reflex in isolated guinea pig ileum in response to boluses of air, water, oil, and cellulose.

Distension of an isolated preparation of guinea pig ileum triggers the peristaltic reflex, a characteristic movement of the intestinal walls which generates luminal pressures and clearance of luminal contents. To determine how the reflex responds to properties of luminal contents, we compared the responses triggered by boluses of air, oil, and cellulose to boluses of Krebs' solution. We found that oil and cellulose increased pressures and contraction length and decreased outflow. Cellulose, but not oil, slowed the velocity with which the contraction propagated and increased the delay with which the end point (upstream edge) of the contraction started to propagate after the lead point (downstream edge). Air tended to produce short contraction segments and high velocity. We conclude that bolus properties such as viscosity determine the response that isolated intestinal segments generate to distension. Response patterns are reflected in contraction length, propagation velocity, and other visual parameters that define wall movements.

Laryngopharyngeal reflux 2002: a new paradigm of airway disease.

Our purpose in writing this supplement is to provide an overview of laryngopharyngeal reflux (LPR). This supplement is not all-encompassing; some of the material presented is controversial; and we recognize that it does represent the bias of physicians at the Center for Voice Disorders of Wake Forest University. Furthermore, we understand that we raise as many questions as we answer. Still, we hope that this supplement will serve as a useful summary of LPR for clinicians, and that it will stimulate others in the research arena.

Inhibition by female sex steroids of peristalsis in the guinea pig small intestine.

AIMS: The effects of steroid hormones on propulsive peristalsis in the intestine were investigated in order to compare their adverse effect profile on this clinically most important motor pattern. METHODS: Peristalsis in isolated segments of the guinea pig small intestine was triggered by luminal distension and recorded via the peristalsis-associated changes of the intraluminal pressure. Drug effects on muscular activity were investigated in a circular muscle preparation of the ileum. RESULTS: Estradiol and progesterone, but not testosterone, hydrocortisone or cholesterol (each at 3-30 microM), caused a prompt and concentration-related increase in the peristaltic pressure threshold at which propulsive muscle contractions were elicited. Mifepristone (RU-486; 30 microM) did not prevent the inhibitory effect of progesterone, but blocked peristalsis per se. Pharmacological blockade of inhibitory neural pathways with N(G)-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor), naloxone (opioid receptor antagonist), apamin or suramin plus pyridoxal phosphate-6-azophenyl-2',4'-disulphonic acid (P2 purinoceptor blockers) counteracted the inhibitory effect of submaximally (10 microM), but not maximally (30 microM), effective concentrations of progesterone. Estradiol and progesterone depressed circular muscle contractions evoked by cholecystokinin octapeptide to a larger degree than responses to the tachykinin NK(1) receptor agonist GR-73,632. CONCLUSION: The peristaltic motor inhibition caused by sex steroids at micromolar concentrations arises primarily from a depressant action on intestinal muscle activity and may be particularly relevant for high-dose regimens of mifepristone.

The left Monti-Malone procedure: Preliminary results in seven cases.

BACKGROUND/PURPOSE: The management of children who have congenital intestinal dysfunction and continuous feces soiling has been improved significantly by the Malone continent caecostomy. When the appendix is not available, the Monti tube represents a good alternative to create a catheterizable conduit. The authors report here 7 cases of left continent colonic access (left Monti-Malone). METHODS: From July 1999 to January 2001 7 patients have been operated on in our unit: 6 spina bifida, 1 cloacal exstrophy. Technically, a ring of descending colon of 1.5 to 2 cm width is isolated with its meso, the Monti's tube fashioned, and implanted into the left colon according to the Malone's technique. Antegrade bowel washouts start 3 weeks after surgery with standard saline (200 to 500 mL) +/- phosphate enemas. A period of 1 to 3 months is needed to adjust to the right enema regimen to get a satisfactory result. RESULTS: The follow-up range is 18 months to 1.5 months. One patient is excluded. The duration of the enemas varies between 10 and 30 minutes, and the number of enemas varies from 1 to every 2 or 3 days. Five children are clean and perform their antegrade enemas after dinner to avoid the embarrassment of post enema leakages. CONCLUSION: Although it is a short series with a short follow-up, the first results collected show a significant shortening of the duration of the enema with excellent outcomes in terms of continence.

[Intragastric stimulation (IGS) for treatment of morbid obesity]. / Intragastrale Stimulation als erste nichtrestriktive und nichtmalabsorptive Behandlungsmethode der morbiden Adipositas.

The technique of implantable gastric stimulator (IGS(R)) placement for treatment of morbid obesity is described. There are three components of the IGS, the programming system, the lead and the electrical stimulator itself. It is placed in the anterior abdominal wall. It is connected to the bioplar lead that is positioned in the muscle wall of the stomach. The nominal parameters were: pulse width 208 micro sec 24 hours per day, pulse rate 40 Hertz and amplitude 6.2-10.0 mA. Fourty eight patients have been treated using techniques that were developed and refined around the world in a prospective open study. 32 and 7 patients, resp. were available for investigation after 6 and 15 months. Twenty-seven (56 %) intra-operative gastric penetrations occurred, as noted on operative gastroscopy, without any clinical sequelae. Six patients (12 %) showed lead dislodgements and a new procedure for lead replacement. There were no operative deaths. All procedures were successfully completed laparoscopically. Two connections required revision (4 %) because the leads were not fully inserted into the lead connector of the generator. No abscess formation or severe complication were noted. The excessive weight loss after 15 months ranged to 32 %. The operation for IGS placement is safe and simple to perform. Attention to technical details is essential for safe performance of the procedure.

Electrical stimulation for propelling endoscopes.

BACKGROUND: Methods are needed for propulsion of endoscopes and wireless video capsules along the small intestine. This work aims to test the hypothesis that electrical stimulation could propel an endoscope by stimulating muscular contraction. METHODS: Prototype acrylic ovoid-shaped devices were constructed with 2 stainless steel electrodes mounted on the tapered section. Five devices 15 to 23 mm diameter with a taper of 28 degrees to 40 degrees (included angle) were tested. When these devices were in contact with the bowel wall, electrostimulation was applied causing circular muscle contraction, which when applied to the taper of the ovoid resulted in forward propulsion of the device. The method does not induce peristalsis but works by stimulating local contraction. The device was tested in the small intestine and esophagus of anesthetized pigs. RESULTS: Electrostimulation caused the ovoid to advance rapidly (6 mm/sec) up and down the esophagus by inducing circular esophageal muscle contraction. When stimulated at 15 Hz with 30-ms pulses, the threshold for movement in the small intestine was 12 mA; at 20 mA the device moved reliably in either direction in the small intestine at speeds of up to 4.5 mm/sec and negotiated tight curves. CONCLUSION: Electrostimulation can move endoscopes in the small intestine.