Motor activity and transit in the autonomically denervated jejunum

Hepatic ductoplasty for iatrogenic Bismuth type 2 bile duct stricture: A case report

•

The article represents recovering treatment of iatrogenic biliary tract injury by laparoscopic cholecystectomy.

•

Biliary tract stricture like Bismuth type 2 successfully treated by hepatic ductoplasty.

•

To emphasize the importance of avoiding biliary stricture is a key to prevent cholangitis and stone recurrences.

Introduction

Biliary enteric anastomosis is a well-known biliary reconstruction method. Anastomosis stricture is one of the complications of this procedure that occurs in some patients over the long-term. We report a successful case of hepatic ductoplasty combined with hepaticojejunostomy (H–J) for the treatment of iatrogenic Bismuth type 2 stricture.

Presentation of case

The patient was a 68-year-woman who had undergone choledochojejunostomy (C–J) 6 years earlier due to bile duct injury after laparoscopic cholecystectomy for cholelithiasis. She complained of recurrent chills and upper back pain. Cholangiography and computed tomography revealed a C–J anastomotic stricture with hepatolithiasis. The diagnosis was reflux cholangitis with hepatolithiasis due to C–J stricture and a fistula between the reconstructed jejunal limb and duodenum. Exploration was performed, and she underwent hepatic ductoplasty with H–J and hepaticolithotripsy. Surgery was performed uneventfully and the patient has remained well subsequently.

Discussion and conclusion

We propose hepatic ductoplasty as a useful technique for the treatment of selected patients with a C–J stricture or narrow hepatic duct.

Utility of hepatobiliary scintigraphy for recurrent reflux cholangitis following choledochojejunostomy: A case report

•

Reflux cholangitis is a common complication of Roux-en-Y choledochojejunostomy.

•

The patient had recurrent postoperative reflux cholangitis.

•

There was no stenosis or calculus in choledochojejunostomy anastomosis.

•

Hepatobiliary scintigraphy detected that the blind loop caused the cholangitis.

•

Hepatobiliary scintigraphy could be adjunct to other examination in diagnosing reflux cholangitis.

•

Hepatobiliary scintigraphy is useful to clarify the mechanism of reflux cholangitis.

Introduction

Reflux cholangitis is a frequent complication of Roux-en-Y choledochojejunostomy.

Presentation of case

A 68-year-old male underwent left lobectomy of the liver, bile duct resection and choledochojejunostomy for intrahepatic cholangiocarcinoma located in Segment 2 of the liver, 40 mm in diameter with a lymph node metastasis 5 years ago. He had frequent recurrences of postoperative reflux cholangitis and hepatic abscesses and was treated with antibiotics each time. Postoperative adjuvant chemotherapy was scheduled, but due to recurrent cholangitis it was difficult. Although double balloon endoscopy for endoscopic retrograde cholangiography was performed, no stenosis was found in the choledochojejunostomy anastomosis, and no defect suspected of calculus and stenosis were found by contrast. Antibiotics had to be administered for a long time because it recurred when antibiotics were discontinued. This time, a tumor 2.0 cm in diameter was detected in segment 7 of the liver on follow – up computed tomography. The preoperative diagnosis was recurrent Intrahepatic cholangiocarcinoma. Hepatobiliary scintigraphy was carried out in preparation for concomitant treatment of his reflux cholangitis. Retention in the blind loop of the choledochojejunostomy was retarded, and the excretion was delayed. Therefore, hepatectomy and resection of the blind loop were performed. We confirmed improvement of stasis in the blind loop on postoperative hepatobiliary scintigraphy. The postoperative course was uneventful, and antibiotics were not required.

Discussion

Hepatobiliary scintigraphy may be able to clarify the mechanism underlying reflux cholangitis.

Conclusion

Hepatobiliary scintigraphy was useful for the treatment of recurrent reflux cholangitis in this case.

Case-control study of the efficacy of retrogastric Roux-en-Y choledochojejunostomy

The traditional, retrocolic/antegastric Roux-en-Y choledochojejunostomy is technically complicated, and the incidence of postoperative complications remains high. Here we report the outcome of 59 consecutively treated patients (study group, SG) that underwent a new choledochojejunostomy method in which the jejunal loop is passed behind the antrum pyloricum (retrogastric route). A retrospective comparison was made between this group of patients and 187 patients (control group, CG) that underwent conventional Roux-en-Y choledochojejunostomy (antegastric route). Baseline clinicopathological characteristics were similar in both groups, except for the BMI, which was significantly higher in the SG. The time spent on constructing the anastomosis, as well as overall postoperative complications, did not differ between groups. Compared with the CG, the incidence of postoperative delayed gastric emptying was decreased in the SG, and the time elapsed before the patients' first postoperative liquid food consumption was shorter. We ascribe these beneficial effects to the superiority of the modified, retropyloric choledochojejunostomy approach, and propose that this surgical technique is particularly suitable for obese patients, especially those with a short ascending bowel loop.

Therapeutic transjejunal endoscopy for the treatment of biliary complications after choledochojejunostomy

The present study aimed to assess the value of endoscopic jejunostomy for post-biliary intestinal anastomosis biliary complications. The clinical data of the endoscopic therapies by jejunal approach for post-biliary intestinal anastomosis biliary complications in 13 patients (16 surgeries in total) were retrospectively analyzed. The surgical success rate was 100% (16/16). Nasobiliary tube detention was performed for 2 patients, plastic stent placement for 5 and biliary metal stent placement for 4. The remaining two patients did not retain any drainage tube or bracket after surgery. The incidence rate of intraoperative anastomotic stenostomia was 76.9% (10/13). A noticeable postoperative decrease in bilirubin levels was observed in 10 patients. The level of gallstone-free patients was 75% (3/4). There were 10 cases in which cholangitis remission or no attack was identified. Post-operative incisional infection occurred in 3 patients, hepatophyma in 1 and an intestinal fistula in 1. Endoscopic therapy by jejunal approach for post-biliary intestinal anastomosis biliary complications has the virtue of being safe, effective and minimally invasive. It has extensive potential applications in clinical practice.

The influence of rejection on graft motility after intestinal transplantation in swine: the possibility of using this method for the real-time monitoring of acute cellular rejection

BACKGROUND

We have previously reported that rejected allografts show dysmotility, which can be detected by real-time monitoring in swine. We examined the correlation between the motility and the mucosal histology to detect rejection at an early stage by real-time monitoring.

METHODS

Intestinal transplantation was performed orthotopically using FK506. The distal segment of the allograft measuring about 20 cm was isolated and exteriorized as "Thiry-Vella" stoma for biopsies. Strain-gage force transducers were attached on a graft for the real-time monitoring of graft motility. The pigs without intestinal transplantation were used as controls (C). The rejection was classified into 4 groups based on the histologic findings: nonrejection, mild rejection, moderate rejection, and severe rejection. Migrating motor complex (MMC) phase 3 was estimated by the following parameters: duration, amplitude, interval, motility index, velocity, and frequency of the propagation.

RESULTS

In the nonrejection group, all parameters were almost the same as in C group. In contrast, in the moderate rejection and severe rejection groups, most of the parameters were significantly lower than those in the C group. In the mild rejection group, the contractility of the MMC was not significantly altered, but the frequency of the propagation decreased significantly.

CONCLUSIONS

The graft motility detected by the real-time strain-gage method correlated closely to the grade of mucosal histology. This method is therefore considered to be useful for detecting rejection at an early stage by examining the frequency of MMC propagation.

Octreotide in the treatment of small intestinal dysfunction after a model of jejunoileal autotransplantation in the pig

Enteric denervation and ischemic injury contribute to dysmotility and malabsorption following intestinal transplantation. We hypothesized that, by prolonging bowel transit and by ameliorating dysmotility, octreotide (OT) may improve cholesterol and bile acid absorption after jejunoileal autotransplantation. Seventeen pigs with fixed food intake underwent either jejunal transection (n = 6), or jejunoileal autotransplantation, which includes extrinsic autonomic denervation, lymphatic interruption, and in situ cold ischemia (n = 11). Five randomly chosen autotransplanted animals received intramuscular long-acting OT (10 mg) once a month. After 8 weeks, weight gain, intestinal transit time, fecal excretion of bile acids and cholesterol, and fractional cholesterol absorption were determined. Jejunal and ileal specimens were collected for histochemical analyses. Plasma cholestenol and campesterol, respective markers of cholesterol synthesis and absorption, were measured after 2 and 8 weeks. Following jejunoileal autotransplantation, octreotide treatment significantly increased the median intestinal transit time from 22.8 to 24.8 h and the median body weight gain from 166 to 187%. Jejunoileal autotransplantation significantly increased fecal bile acid excretion, plasma cholestenol, and bacterially modified fecal neutral sterols, and decreased absorption of cholesterol, plasma campesterol, and biliary cholesterol secretion. These changes were not significantly modified by OT treatment. Bowel wall and mucosal structure, mucosal proliferation, and weight or microvilli showed no statistically significant differences between autotransplanted animals with or without OT treatment. Findings of the present study suggest that octreotide prolongs intestinal transit time and improves weight gain after jejunoileal autotransplantation, but has no effect on malabsorption of cholesterol and bile acids.

Effects of transection and extrinsic denervation and a model of autotransplantation of the porcine jejunoileum on cholesterol biodynamics

BACKGROUND/PURPOSE

Small bowel transplantation impairs enteric function, necessitating transection, extrinsic denervation, and ischemia-reperfusion of the small intestine. The authors investigated how each of these nonimmunologic insides of the transplantation procedure modulates biodynamics of cholesterol and absorption of lipids.

METHODS

Twenty-three pigs with similar food, cholesterol, and fat intake underwent sham laparotomy (group 1), transection (group 2), extrinsic jejunoileal denervation (group 3), or a model of autotransplantation, including extrinsic jejunoileal denervation with in situ ischemia-reperfusion (group 4). Serum lipids, absorption, and excretion of cholesterol, bile acids, and fat were determined after 8 weeks. Plasma cholesterol precursors and plant sterols, respective markers of cholesterol synthesis, and absorption, were measured after 2 and 8 weeks.

RESULTS

When compared with sham laparotomy and transection groups, denervation and autotransplantation significantly decreased weight gain and increased plasma cholesterol precursors and fecal excretion of bile acids. In relation to sham operated animals, transection alone modestly increased plasma plant sterols at 2 weeks and biliary secretion and mass absorption of cholesterol. The latter changes were not observed after denervation or autotransplantation, ie, fractional and total absorption of cholesterol were significantly decreased in autotransplanted pigs when compared with transected controls. As compared with all the other groups, autotransplantation significantly increased bacterial metabolites of neutral sterols in feces and net fecal elimination of cholesterol, mainly as bile acids.

CONCLUSIONS

Extrinsic autonomic denervation of the jejunoileum, with or without synchronous ischemia-reperfusion, results in increased cholesterol synthesis, bile acid malabsorption, and decreased weight gain. Cholesterol malabsorption may develop gradually after intestinal autotransplantation, and even a short period of ischemia further impairs absorptive function of the denervated jejunoileum, resulting in increased fecal elimination of cholesterol mainly as bile acids.

Role of extrinsic innervation in modulating nitrergic transmission in the canine ileocolonic region

The human colon can dilate, often to life-threatening proportions. Our aim was to explore nitrergic mechanisms underlying colonic dilation in conscious dogs with enterically isolated ileocolonic loops either extrinsically innervated (n = 4) or extrinsically denervated (n = 4). We recorded phasic pressures in ileum and ileocolonic sphincter (ICS), colonic tone, compliance, and relaxation during ileal distension. By NADPH-diaphorase histochemistry, we assessed effects of extrinsic denervation and enteric isolation on nitrergic fibers. Extrinsic denervation increased phasic pressures in ileum, ICS, and colon and abolished ICS and colonic relaxation in response to ileal distension. The nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine (L-NNA) increased phasic pressures at all sites and ICS tone but did not abolish colonic relaxation during ileal distension in innervated loops. L-NNA reduced compliance and induced colonic high-amplitude propagated contractions in denervated loops. The NOS substrate donor L-arginine reversed effects of L-NNA. The number of NADPH-diaphorase fibers increased in both enterically isolated preparations. Nonnitrergic extrinsic nerve pathways mediate reflex colonic relaxation during ileal distension. Enteric isolation augments the number of NOS fibers, an effect not modified by extrinsic denervation.

Effects of intestinal transplantation on postprandial motility and regulation of intestinal transit

BACKGROUND

The effects of intestinal transplantation on gut motility have not been completely defined. In this study we examine the effects of ileal transplantation on ileal smooth muscle contractility, together with gastroduodenal emptying, intestinal flow, and transit rates in a canine model of short-gut syndrome.

METHODS

Animals (n = 22) were instrumented with strain gauge transducers, collection cannulae, and infusion catheters to assess motility, intestinal flow and transit rates, and gastroduodenal emptying. Ten animals served to define normal parameters. Six animals underwent a 70% resection of the proximal small intestine to serve as short-gut controls. Six animals underwent removal of a 100-cm segment of the ileum, with cold storage, and autotransplantation the following day combined with a 70% resection of proximal bowel.

RESULTS

Transplant animals exhibited delayed gastroduodenal emptying, reduced intestinal flow rates, and postprandial phasic contractions that were similar to short-gut controls. However, transplant animals experienced rapid intestinal transit compared with short-gut controls (4.8 +/- 0.4 cm/min vs 2.0 +/- 0.3 cm/min; mean +/- SEM; P <.05).

CONCLUSIONS

The transplanted intestine, even with 18 hours of cold storage, exhibits a relatively normal postprandial motor response. However, adaptive responses of the transplanted intestine, such as regulation of intestine transit, may be impaired by neuromuscular injury associated with denervation or ischemia.

Upper jejunal motility after pancreatoduodenectomy according to the type of anastomosis, pancreaticojejunal or pancreaticogastric

BACKGROUND

The goal of this study was to compare upper jejunal motor patterns after Billroth II pancreatoduodenectomy according to the type of pancreatic anastomosis (pancreaticojejunostomy [PJA] or pancreaticogastrostomy [PGA]) and the presence or absence of postoperative symptoms.

STUDY DESIGN

Manometric recordings during fasting and after a 750-kcal meal were performed in the afferent limb in 12 patients (7 PJA, 5 PGA) and in the efferent limb in 15 other patients (7 PJA, 8 PGA) with a postoperative delay of 15+/-6 days and 3.9+/-2.2 months respectively. Patient data were compared to those of 20 healthy controls.

RESULTS

During fasting, the 2 main abnormal findings were a higher incidence (p < 0.05) and a slower migration velocity (p < 0.01) of incomplete phase III by comparison with that recorded in controls. No difference for phase III was observed between the 2 surgical procedures regardless of recording site. Trimebutine, 100 mg intravenously, induced a phase III in 89% (24 of 27) of the patients. Delay of motor response varied from 5 to 10 minutes without difference between the recording site; it was less than 2 minutes in 100% of controls. Trimebutine-induced phase III showed similar propagation abnormalities to the spontaneous phase III. Duration of the fed pattern (p < 0.001) and motor index (p < 0.001) were significantly lower than in controls after the meal, in both limbs, whatever the type of anastomosis. Differences between the 2 surgical procedures were a slower migration velocity of phase III (p < 0.01) and a lower postmeal motor index (p < 0.05) in the efferent limb after PJA than after PGA. Nine of 27 patients were symptomatic. In these 9 patients, mean phase III migration velocity was slower (p < 0.001), and mean area under the postprandial curve was higher (p < 0.01) than in asymptomatic patients. Propagated clusters of contractions were only found in symptomatic patients and in the afferent limb.

CONCLUSIONS

Pancreatoduodenectomy is associated with significant motor disturbances, mainly slower phase III and a reduced fed pattern, in the upper jejunum, at least during the first 3 postoperative months. Few motor differences were observed between PGA and PJA pancreatic anastomosis. A lesser occurrence of postsurgical motor anomalies does not appear to be an argument for preferring PGA to PJA.

Adaptive lipid metabolism after ileal autotransplantation in pigs with proximal gut resection

BACKGROUND

Transplantation of the small intestine impairs intestinal absorptive function, but the adaptive response of a segmental graft is unknown. The aim of this study was to investigate the effects of ileal autotransplantation on the adaptive absorption and metabolism of lipids in pigs that had undergone proximal gut resection.

METHODS

Serum lipids, plasma vitamins A and E, absorption and excretion of cholesterol, bile acids and fat, plasma cholesterol precursor and plant sterol proportions to cholesterol (respective markers of cholesterol synthesis and absorption), enteric structure, and transit were determined 4, 8, and 14 weeks after 75% proximal resection with (n = 15) or without (n = 15) autotransplantation of the remaining ileum.

RESULTS

As compared with pigs that underwent proximal gut resection, the additional autotransplantation reduced the adaptive increase in total serum and high-density lipoprotein cholesterol, plasma plant sterol proportions and vitamin E concentrations, cholesterol and fat absorption efficiency, and villus height (p < 0.05 for all) during the 14 postoperative weeks and resulted in increases of up to 4.6, 2.7, 1.3, and 2.1 times the plasma cholesterol precursors (p < 0.005), fecal excretion of bile acids (p < 0.0005), neutral steroids (p < 0.005), and net elimination of cholesterol (p < 0.0005), respectively. Cholesterol and fat absorption and plasma plant sterols were significantly enhanced between 8 and 14 weeks after autotransplantation (p < 0.05, p < 0.005, and p < 0.05, respectively), whereas fecal elimination of cholesterol remained increased until the end of the follow-up.

CONCLUSIONS

Autotransplantation of the ileum in pigs that have undergone proximal small bowel resection disturbs the adaptive absorption of cholesterol, bile acids, fat, and fat-soluble vitamins, resulting, through increased fecal elimination of cholesterol, in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.

Postprandial motor activity and its relationship to transit in the canine ileum

BACKGROUND

The purpose of this study was to elucidate the mechanism of reduced intestinal transit rate in the ileum as compared with the jejunum.

METHODS

Twenty-one dogs were each instrumented with 12 strain gauge transducers, 2 collection cannulas, and an infusion catheter defining a 100 cm study in the midjejunum (n = 11) and midileum (n = 10). Postprandial motor activity and intestinal transit were measured 1 hour after ingestion of a 650 kcal solid meal. Contractile activity was analyzed by means of computer programs that determine frequency, amplitude, and propagation behavior of circular smooth muscle contractions.

RESULTS

Postprandial ileal contractions occurred with greater frequency (13.7 +/- 2.5 versus 11.5 +/- 0.4; p = 0.04) and displayed a higher incidence of propagation (61% +/- 2% versus 44% +/- 3%; p = 0.0001) than jejunal contractions, but traveled at significantly slower rates (1.0 +/- 0.7 cm/sec vs 3.7 +/- 0.9 cm/sec; p = 0.0001). The net result was significantly slower transit in the ileum compared with the jejunum (4.7 +/- 0.7 cm/min versus 13.1 +/- 1.5 cm/min; p = 0.0006). Within each region, transit correlated with parameters of propagating contractions. Stepwise regression of the combined data revealed that contraction velocity was the most important variable determining intestinal transit rate (r = 0.64; p < 0.001).

CONCLUSIONS

Contrary to previous thinking, postprandial ileal contractions display a high degree of temporal and spatial organization. Slow ileal transit is mainly due to reduced propagation velocity, which is intrinsic to the circular smooth muscle.

Cholesterol absorption and synthesis after autotransplantation of porcine ileum

BACKGROUND

Cholesterol, long-chain fatty acids, and fat-soluble vitamins are absorbed mainly in the upper small intestine and bile acids in the terminal ileum. This study determined the consequences of ileal autotransplantation on cholesterol metabolism, plasma fatty acids, and vitamin A absorption.

METHODS

Plasma lipids, cholesterol precursors, plant sterols, cholestanol, fatty acids, vitamin A absorption, and animal growth were studied for 3 months after transection (n = 5), jejunal (50%) resection (n = 7), jejunal (50%) resection combined with orthotopic ileal autotransplantation (n = 7), and enterectomy (n = 7).

RESULTS

Cholesterol precursor to cholesterol proportions in plasma (reflect cholesterol synthesis) remained unchanged after transection and jejunal resection. The plasma plant sterol proportions (reflect cholesterol absorption) and retinol absorption increased after transection and less significantly after jejunal resection, whereas plasma fatty acid compositions were virtually unchanged. Transplantation of ileum and enterectomy amended up to sixfold the precursor proportions (p < 0.05 versus transection or jejunal resection) and impaired body weight gain. The plant sterol proportions, vitamin A absorption, and plasma cholesterol levels, respectively, were significantly (p < 0.05) decreased after transplantation when compared with those of the transected control group but remained markedly higher than those in the enterectomized group. Linoleic acid was significantly (p < 0.05 versus transection) decreased, whereas monoenoic fatty acids and eicosatrienoic acid were increased (p < 0.05 versus jejunal resection) in plasma lipids.

CONCLUSIONS

These results indicate that autotransplantation of ileum in pigs that have undergone jejunectomy impairs sterol, essential fatty acid, and vitamin A absorption so that plasma cholesterol levels decrease despite markedly increased cholesterol synthesis and that these changes clearly exceed those found after jejunal resection alone.

Ileal nutritional function after one-stage orthotopic ileum transplantation in the growing pig: reversal of lethal short bowel syndrome

Intestinal isolation is associated with hypoplasia of defunctioned mucosa and reduction in the segmental absorption, whereas the presence of luminal nutrition is essential for the expression of the ileal adaptive response after proximal small bowel resection. On the other hand, intensive postoperative graft monitoring is obligatory because of the disastrous consequences of small bowel graft rejection. Thus, the authors sought to develop an experimental ileum transplantation model that provided immediate graft placement in bowel continuity, together with readily available graft monitoring connection through a proximal Roux-en-Y enterostomy. Four groups of pigs were prepared: RESTX (n = 9), proximal 50% small bowel resection with simultaneous orthotopic ileum autotransplantation; RES (n = 7), proximal 50% small bowel resection; NONRES (n = 6), transection; and SB (n = 5), short bowel. Early (1 to 4 weeks) and long-term (5 to 12 weeks) studies of animal growth, nutritional status, disaccharide absorption, water and electrolyte balances, and liver function were performed after ileum autotransplantation (IAT) in relation to small intestine of variable length with undivided mesentery (intact neural and lymphatic connections). The perioperative transplantation mortality rate remained at about 10%. Reasons not related to the transplantation procedure accounted for the late complication rate of 38%. In the ileum autotransplantation (RESTX) group, weight gain was recovered 2 to 3 weeks after transplantation, and the mean weight reached the preoperative level at 5 weeks. The SB pigs underwent progressive weight loss. The transection (NONRES) and proximal resection (RES) animals gained weight at similar rates. IAT had no effect on the plasma protein concentrations. Proximal resection, with or without IAT, was associated with depressed plasma cholesterol contents in the early period. Plasma cholesterol levels amended long-term, after both IAT and proximal resection. IAT resulted in deficient intraluminal processing of maltose, whereas isolated proximal resection tended to enhance disaccharide absorption early after the surgery. The short bowel pigs were not able to preserve sufficient nutritional status, and demonstrated a marked decline in the hemoglobin, protein, and cholesterol levels. No biochemical signs suggestive of potential liver damage caused by portocaval graft vascularization were recognized. These findings suggest that one-stage ileum autotransplantation provides sufficent absoprtive capacity to reverse otherwise lethal short bowel syndrome in the growing pig. However, transplantation disturbs the in vivo absorptive function of the nonrejecting ileum. Long-term impairment in disaccharide absorption may be partially related to an altered intestinal adaptive response secondary to proximal resection when combined with simultaneous transplantation. The authors developed this ileal small bowel transplantation model using rapidly growing pigs, wherein body weight gain represents an objective parameter of intestinal absorptive function. Only this type of animal model can yield clinically relevant data in the evaluation of a transplant's ability to provide sufficient nutritional function in a growing recipient.

Effects of enteral feedback inhibition on motility, luminal flow, and absorption of nutrients in proximal gut of minipigs

We wanted to clarify whether the postprandial intestinal feedback control activated by nutrients in the distal gut exerts different effects on motility, transit of digesta, and absorption of nutrients in the proximal gut. Additionally, interrelationships among motility, transit, and absorption were to be elucidated because these relationships have only been investigated in the fasted state. In five minipigs, a 150-cm segment of the proximal jejunum was isolated by two cannulas. Motility of the jejunal segment was recorded by multiple strain gauges and analyzed by computerized methods. Markers (Cr- and Cu-EDTA) were used for the measurement of the flow rate, transit time, and absorption of nutrients. After a meal, the test segment was perfused with 2 kcal/min of an elemental diet over a period of 90 min. A feedback inhibition was activated by infusion of nutrients into the midgut at rates of 1-4 kcal/min. Saline was infused as control. With increasing energy loads infused into the midgut, the motility index and the length of contraction waves decreased, whereas the incidence of stationary contractions increased, ie, the motility changed from a propulsive to a segmenting pattern. These modulations of motility were associated with a linear decrease in the flow rate and a linear increase in transit time. Flow and transit were linearly correlated with each other. Additionally, the reduction in flow rate and the delay in luminal transit were associated with a linear increase in the absorption of nutrients. However, the increase in absorption induced by the feedback mechanism was small (7.3-13.4%) compared to the marked inhibition of the motility parameters (54-64%), the flow rate (59%), and the delay of transit (5.8-fold). Feedback control primarily modulated motor patterns and luminal flow, whereas the small increase in absorption was only a side effect due to the longer contact time of the nutrients with the mucosa.