复方嗜酸乳杆菌片对感染性腹泻患者胃肠道症状的影响

目的 应用复方嗜酸乳杆菌片治疗感染性腹泻,观察微生态制剂对患者胃肠道症状的影响。方法 选择100例感染性腹泻患者,均来自青岛大学附属中心医院,采用随机数字表法随机分为A、B组。其中A组患者（80例）单用复方嗜酸乳杆菌片（1.0 g/次,3次/d,口服）治疗;B组患者（20例）单用利福昔明片（0.2 g/次,4次/d,口服）治疗。两组患者均采用配对设计方法,治疗前进行胃肠道症状分级评分,包括单个症状（腹痛、腹胀、腹泻频率、大便性状）的评分和上述症状的总评分。治疗3 d后门诊随访或电话随访,再次进行胃肠道症状分级评分,比较治疗前后患者的胃肠道症状评分改善情况并判断疗效以及治疗中的不良反应。结果 两组患者的总有效率分别为78.75％和85.00％,差异无统计学意义（P>0.05）。两组患者治疗过程中均未见不良反应。复方嗜酸乳杆菌片治疗后患者腹胀、腹泻频率、大便性状的症状评分和症状总评分较治疗前显著降低,差异有统计学意义（P0.05）。结论 复方嗜酸乳杆菌片治疗感染性腹泻能达到满意的疗效,可改善患者腹胀、腹泻频率、大便性状等胃肠道症状。     

Disodium Cromoglycate Reverses Colonic Visceral Hypersensitivity and Influences Colonic Ion Transport in a Stress-Sensitive Rat Strain

The interface between psychiatry and stress-related gastrointestinal disorders (GI), such as irritable bowel syndrome (IBS), is well established, with anxiety and depression the most frequently occurring comorbid conditions. Moreover, stress-sensitive Wistar Kyoto (WKY) rats, which display anxiety- and depressive-like behaviors, exhibit GI disturbances akin to those observed in stress-related GI disorders. Additionally, there is mounting preclinical and clinical evidence implicating mast cells as significant contributors to the development of abdominal visceral pain in IBS. In this study we examined the effects of the rat connective tissue mast cell (CTMC) stabiliser, disodium cromoglycate (DSCG) on visceral hypersensitivity and colonic ion transport, and examined both colonic and peritoneal mast cells from stress-sensitive WKY rats. DSCG significantly decreased abdominal pain behaviors induced by colorectal distension in WKY animals independent of a reduction in colonic rat mast cell mediator release. We further demonstrated that mast cell-stimulated colonic ion transport was sensitive to inhibition by the mast cell stabiliser DSCG, an effect only observed in stress-sensitive rats. Moreover, CTMC-like mast cells were significantly increased in the colonic submucosa of WKY animals, and we observed a significant increase in the proportion of intermediate, or immature, peritoneal mast cells relative to control animals. Collectively our data further support a role for mast cells in the pathogenesis of stress-related GI disorders.     

Plasma and tissue alterations of peptide YY and enteroglucagon in rats after colectomy.

Peptide YY (PYY) and enteroglucagon are produced by endocrine cells of the colonic mucosa. PYY inhibits upper gastrointestinal motility, and enteroglucagon is trophic for small bowel mucosa. Adaptive increase in the production and release of these peptides may improve functional results after colorectal resections. We hypothesized that if segments of the colon were resected, then production and release of PYY and enteroglucagon would increase in the remaining segments of bowel. Animals which underwent colonic transections and partial resections had transient elevations of PYY up to 250 +/- 80 pmol/L, which dropped to control group levels in the second week following surgery. Rats with an abdominal colectomy had significantly greater PYY levels than all other groups from the third (208 +/- 30 pmol/L) to the thirty-eighth (100 +/- 16 pmol/L) week of the study. Circulating levels of enteroglucagon were elevated to 156 +/- 35 pmol/L in rats with a right hemicolectomy during the first week following surgery. Enteroglucagon levels did not significantly vary in the other groups studied. Both tissue PYY (413 +/- 33 pmol/gram) and tissue enteroglucagon (171 +/- 17 pmol/gram) were significantly elevated in the rectums of the rats with an abdominal colectomy, as compared to all other groups. The elevated tissue levels may thus account for the ability to maintain elevated plasma PYY. Double immunogold labeling of endocrine cells in the colorectal tissue for PYY and enteroglucagon revealed both peptides within the same endocrine cells and secretory granules. These studies support the hypothesis that circulating levels of PYY are elevated after major colonic resections and suggest that L-type endocrine cells may participate in adaptive responses which improve intestinal function following colonic surgery.     

Altered temporal characteristics of the rectoanal inhibitory reflex in patients with abdominal distension

The rectoanal inhibitory reflex (RAIR) is important in gas and stool evacuation. We examined RAIR features in patients with chronic constipation who exhibited bloating with and without abdominal distension, to determine whether alterations in RAIR may be a factor in the pathogenesis of abdominal distension. Seventy-five female patients with chronic constipation with or without abdominal distension were included in the study. The presence or absence of abdominal distension was assessed according to the Rome II questionnaire. All patients underwent both RAIR and rectal sensitivity testing, and specific RAIR parameters were analyzed. Patients were divided into two groups: abdominal bloating with distension (D, n = 55) and abdominal bloating without distension (ND, n = 20). D had a longer time to the onset of anal sphincter inhibition (latency of inhibition) (P = 0.03) compared with ND. In logistic regression analysis, a combination of age, latency of inhibition and the time measured from onset of inhibition to the point of maximum inhibition predicted abdominal distension (P = 0.002). There were no differences between groups for the time from point of maximum inhibition to recovery and for the percentage of internal anal sphincter relaxation. This is the first study to examine the role of RAIR in patients with abdominal distension. Female patients with constipation and abdominal distension exhibited differences in the temporal characteristics of, but not in the degree of, anal sphincter relaxation compared with patients without distension. Since this study was uncontrolled, further studies are necessary to determine the contribution of altered anorectal reflexes to abdominal distension.     

Anatomic modifications in the enteric nervous system of piebald mice and physiological consequences to colonic motor activity

It has been assumed that in piebald lethal mice that develop megacolon, impaired colonic motor activity is restricted to the aganglionic distal colon. Peristaltic mechanical recordings, immunohistochemistry, and quantitative PCR were used to investigate whether regions of the colon, other than the aganglionic segment, may also show anatomical modifications and dysfunctional colonic motor activity. Contrary to expectations, colonic migrating motor complexes (MMCs) were absent along the whole colon of piebald lethal homozygote mice and severely impaired in heterozygote siblings. Aganglionosis was detected not only in the distal colon of piebald homozygote lethal mice (mean length: 20.4 +/- 2.1 mm) but also surprisingly in their heterozygote siblings (mean length: 12.4 +/- 1.1 mm). Unlike homozygote lethal mice, piebald heterozygotes showed no signs of megacolon. Interestingly, mRNA expression for PGP 9.5 was also dramatically reduced (by 71-99%) throughout the entire small and large bowel in both homozygote lethal and heterozygous littermates (by 67-87%). Histochemical staining confirmed a significant reduction in myenteric ganglia along the whole colon. In summary, the piebald mutation in homozygote lethal and heterozygote siblings is associated with dramatic reductions in myenteric ganglia throughout the entire colon and not limited to the distal colon as originally thought. Functionally, this results in an absence or severe impairment of colonic MMC activity in both piebald homozygote lethal and heterozygote siblings, respectively. The observation that piebald heterozygotes have an aganglionic distal colon (mean length: 12 mm) but live a normal murine life span without megacolon suggests that aganglionosis >12 mm and the complete absence of colonic MMCs may be required before any symptoms of megacolon arise.     

经肠镜导入益生菌对肠易激综合征治疗的可行性研究

目的 观察经肠镜导入益生菌对肠易激综合征（IBS）患者症状的影响及可能的不良反应。方法 选择福建医科大学附属第一医院就诊的IBS患者,入选患者均符合IBS罗马IV诊断标准并同意进入本研究。患者肠镜检查完成时于右半结肠单次喷洒33.6 mg/mL的双歧杆菌三联活菌‒生理盐水混悬液100 mL,第0、2和4周进行粪便Bristol分型、腹痛视觉评分（VAS）、结肠症状评分和IBS严重程度调查表评分（IBS-SSS）;第0、4周进行医院焦虑抑郁量表（HADS）测定。结果 入选患者中共有5例IBS便秘型（IBS-C）、13例IBS腹泻型（IBS-D）患者完成研究,年龄分别为（49.4±10.0）岁和（36.1±8.9）岁,男女比例分别为1∶0.66和3.3∶1,均无严重不良反应发生。IBS-C组患者症状指标均无显著改善（P>0.05）,该组患者提前终止。IBS-D组患者综合疗效指数0.692,与第0周相比,第2和4周患者的粪便Bristol分型、腹痛VAS评分、症状总积分和IBS-SSS评分均显著下降（P0.05）。结论 经肠镜单次双歧杆菌三联活菌混悬液喷洒可安全有效地改善IBS-D患者的肠道症状,但对IBS-C患者无效。     

1,2-Dimethylhydrazine-induced alterations in lipid peroxidation in preneoplastic and neoplastic colonic tissues

To determine whether alterations in lipid peroxidation existed in the preneoplastic and neoplastic colonic tissues of animals treated with the procarcinogen 1,2-dimethylhydrazine, rats were injected subcutaneously with this agent (20 mg/kg body weight per week) or diluent for 5, 10, 15 and 26 weeks. At each of these time periods, animals from both groups were sacrificed, their distal colonic mucosa and/or tumors harvested, and examined and compared with respect to malondialdehyde and lipofuscin-like pigments levels. Additionally, at 26 weeks, the fatty acid composition of microsomes prepared from control, 'uninvolved' and tumor colonic tissues were analyzed and compared. The results of these experiments demonstrated that: (1) the levels of these products of lipid peroxidation were similar in the distal colons of all animals at 5 and 10 weeks; (2) at 15 weeks, however, lipid peroxidation was decreased in the distal colons of animals treated with dimethylhydrazine; (3) at 26 weeks, the levels of these products of lipid peroxidation remained lower in dimethylhydrazine-treated distal 'uninvolved' colonic mucosa and was, moreover, markedly decreased in colonic tumors; and (4) at this latter time period, differences in the fatty acid composition between tumor, 'uninvolved' and control tissues were found. These differences, however, did not appear to underlie the changes noted in the lipid peroxidation products seen in these tissues. Taken together, these findings suggest that alterations in lipid peroxidation may be involved in the colonic malignant transformation process in this experimental model.     

Corticosteroid receptor-mediated mechanisms in the amygdala regulate anxiety and colonic sensitivity

Our previous studies have shown that stereotaxic implantation of corticosterone (Cort) onto the central amygdaloid nucleus increases both anxiety and colonic sensitivity. The goal of this study was to examine the relative importance of amygdaloid glucocorticoid (GR) and mineralocorticoid receptor (MR)-mediated mechanisms in the induction of anxiety and colonic hypersensitivity. In male Fischer 344 rats, Cort or cholesterol micropellets were stereotaxically implanted bilaterally at the dorsal boundary of the central amygdaloid nucleus either alone or in combination with a GR antagonist, mifepristone, or a MR antagonist, spironolactone. Anxiety was assessed on the elevated plus maze and quantified as the percentage of time spent in open arm exploration. Colonic sensitivity was measured by recording a visceromotor response, the number of abdominal muscle contractions in response to colorectal distension. In Cort-implanted rats there was a significant reduction in the percentage of time spent in the open arms of the elevated plus maze compared with cholesterol controls, indicating increased anxiety. Furthermore, colonic hypersensitivity was observed in response to colorectal distension compared with rats with cholesterol implants. In rats with Cort implants combined with either a GR or MR antagonist, there was a significant inhibition of anxiety and colonic hypersensitivity. Our data suggest that both GR and MR play a critical role in Cort-induced anxiety and colonic hypersensitivity.     

Attenuation of the colorectal tonic reflex in female patients with irritable bowel syndrome

Alterations in normal intestinointestinal reflexes may be important contributors to the pathophysiology of irritable bowel syndrome (IBS). Our aims were to compare the rectal tonic responses to colonic distension in female IBS patients with predominant constipation (IBS-C) and with predominant diarrhea (IBS-D) to those in healthy females, both fasting and postprandially. Using a dual barostat assembly, 2-min colonic phasic distensions were performed during fasting and postprandially. Rectal tone was recorded before, during, and after the phasic distension. Colonic compliance and colonic sensitivity in response to the distension were also evaluated fasting and postprandially. Eight IBS-C patients, 8 IBS-D patients, and 8 age- and sex-matched healthy subjects (group N) participated. The fasting increments in rectal tone in response to colonic distension in both IBS-C (rectal balloon volume change -4.6 +/- 6.1 ml) and IBS-D (-7.9 +/- 4.9 ml) were significantly reduced compared with group N (-34 +/- 9.7 ml, P = 0.01). Similar findings were observed postprandially (P = 0.02). When adjusted for the colonic compliance of individual subjects, the degree of attenuation in the rectal tonic response in IBS compared with group N was maintained (fasting P = 0.007; postprandial P = 0.03). When adjusted for colonic sensitivity there was a trend for the attenuation in the rectal tonic response in IBS patients compared with group N to be maintained (fasting P = 0.07, postprandial P = 0.08). IBS patients display a definite attenuation of the normal increase in rectal tone in response to colonic distension (colorectal reflex), fasting and postprandially. Alterations in colonic compliance and sensitivity in IBS are not likely to contribute to such attenuation.     

1,2-Dimethylhydrazine-induced alterations in N1-acetylspermidine levels in rat distal colonic mucosa: effects of 2-difluoromethylornithine

Recently, our laboratory has demonstrated that N1-acetylspermidine levels were increased in the distal colonic mucosa of rats administered 1,2-dimethylhydrazine for 15 and 26 weeks. In order to further explore the possible role of this acetylated polyamine in the malignant transformation process induced by this carcinogen, groups of rats were subcutaneously injected weekly with dimethylhydrazine (20 mg/kg body wt.) or diluent for 5, 10, 15 and 26 weeks +/- 1% 2-difluoromethylornithine in the drinking water. The latter agent, an irreversible inhibitor of ornithine decarboxylase, has previously been shown to inhibit colonic tumor formation in this experimental model. At each of these time periods, rats from each group were killed, their proximal and distal colonic mucosa harvested and examined, and compared with respect to polyamine levels, including N1-acetylspermidine, as well as the activities of ornithine decarboxylase, S-adenosylmethionine decarboxylase, spermidine N1-acetyltransferase and polyamine oxidase. The results of these experiments demonstrated that: (1) N1-acetylspermidine levels in the proximal colonic segment of all animals were similar at each time point; (2) N1-acetylspermidine levels were also similar in the distal colons of all animals at 5 and 10 weeks. At 15 weeks, however, the level of N1-acetylspermidine was increased in the dimethylhydrazine-treated distal colonic segment secondary to increases in the activity of spermidine N1-acetyltransferase; and (3) at 26 weeks, the level of this acetylated polyamine remained higher in dimethylhydrazine-treated distal 'uninvolved' colonic mucosa and was markedly elevated in colonic tumors; (4) co-administration of difluoromethylornithine decreased the elevated levels of N1-acetylspermidine to control values in the distal colons of animals treated with carcinogen for 15 and 26 weeks; and (5) difluoromethylornithine markedly reduced the number of tumors induced by dimethylhydrazine in the distal but not proximal colonic mucosa at 26 weeks.     

Hepatic myelolipoma in two Goeldi's monkeys from South America held captive

Two cases of hepatic myelolipoma in Goeldi's monkeys from South America are described. One was a female evaluated due progressive abdominal distension. Ultrasound and computed tomography detected hepatic mass. Partial hepatectomy was performed, but the monkey died after surgery. Case 2 was a male that died suddenly, showing non‐specific clinical signs.     

Characterization of motor patterns in isolated human colon: are there differences in patients with slow-transit constipation?

The patterns of motor activity that exist in isolated full-length human colon have not been described. Our aim was to characterize the spontaneous motor patterns in isolated human colon and determine whether these patterns are different in whole colons obtained from patients with slow-transit constipation (STC). The entire colon (excluding the anus), was removed from patients with confirmed STC and mounted longitudinally in an organ bath ～120 cm in length, containing oxygenated Krebs' solution at 36°C. Changes in circular muscle tension were recorded from multiple sites simultaneously along the length of colon, by use of isometric force transducers. Recordings from isolated colons from non-STC patients revealed cyclical colonic motor complexes (CMCs) in 11 of 17 colons, with a mean interval and half-duration of contractions of 4.0 ± 0.6 min and 51.5 ± 15 s, respectively. In the remaining six colons, spontaneous irregular phasic contractions occurred without CMCs. Interestingly, in STC patients robust CMCs were still recorded, although their CMC pacemaker frequencies were slower. Intraluminal balloon distension of the ascending or descending colon evoked an ascending excitatory reflex contraction, or evoked CMC, in 8 of 30 trials from non-STC (control) colons, but not from colons obtained from STC patients. In many control segments of descending colon, spontaneous CMCs consisted of simultaneous ascending excitatory and descending inhibitory phases. In summary, CMCs can be recorded from isolated human colon, in vitro, but their intrinsic pacemaker frequency is considerably faster in vitro compared with previous human recordings of CMCs in vivo. The observation that CMCs occur in whole colons removed from STC patients suggests that the intrinsic pacemaker mechanisms underlying their generation and propagation are preserved in vitro, despite impaired transit along these same regions in vivo.     

Decay-accelerating factor deficiency increases susceptibility to dextran sulfate sodium-induced colitis: role for complement in inflammatory bowel disease

Decay-accelerating factor (DAF or CD55) is expressed on colonic epithelial cells but its function in the mucosa is unknown. In humans, a proportion of DAF-deficient (Cromer INAB) patients develop inflammatory bowel disease (IBD). To evaluate how DAF deficiency may contribute to gut inflammation and thus could play a role in IBD pathogenesis, we compared the severity of dextran sulfate sodium-induced colitis in Daf1 gene-targeted and control mice. Seven days after consuming 3% dextran sulfate sodium in their drinking water, Daf1(-/-) mice suffered markedly greater weight loss (-24.7 +/- 7.5% vs -14.2% +/- 4.9%), exhibited uniformly bloody diarrhea as compared with soft stool in control mice, developed shortened colons, and had larger spleens. Histological examination of distal colons showed massively increased neutrophilic and mononuclear cell infiltration, greater epithelial cell destruction, and increased ulcerations. Cytokine production in organ cultures of colonic explants showed increased levels of IL-12 and IL-6. Fourteen days after switching back to regular water, in contrast to the Daf1(+/+) controls which showed little stool abnormality, all Daf1(-/-) mice continued to have diarrhea. Organ culture cytokine measurements at this time point, i.e., the end of the recovery phase, showed markedly increased levels of IL-10 (6-fold), IL-12 (4-fold), and IL-6 (2-fold), as well as TNF-alpha (>10-fold) compared with the controls. Our findings argue that, as shown for IL-10 in IL-10(-/-) mice and IL-2 in IL-2(-/-) mice, DAF control of complement additionally is important in regulating gut homeostasis and consequently its activity may participate in protecting against IBD.     

Cholinergic stimulation enhances colonic motor activity, transit, and sensation in humans

The cholinesterase inhibitor neostigmine indirectly stimulates muscarinic M(1)/M(2)/M(3) receptors, thereby reducing colonic distension in acute colonic pseudo-obstruction. We investigated the dose-response profile for the colonic sensorimotor effects of neostigmine and bethanechol, a direct muscarinic M(2)/M(3) agonist in humans. A barostat-manometric assembly recorded phasic pressures, tone, and pressure-volume relationships (compliance) in the descending colon and rectum of 30 healthy subjects who received intravenous neostigmine (0.25, 0.75, or 1.5 mg; n = 15) or subcutaneous bethanechol (2.5, 5, or 10 mg; n = 15). Sensation to luminal distension was also assessed. Thereafter, the effects of neostigmine and bethanechol on colonic transit (geometric center) were compared with those of saline by scintigraphy in 21 subjects. Both drugs increased colonic phasic pressure activity, reduced rectal compliance, and enhanced urgency during rectal distension. Neostigmine also reduced colonic and rectal balloon volumes, reflecting increased tone by an average of 12% and 25% for the highest dose, respectively. Only neostigmine reduced colonic compliance, accelerated colonic transit [mean geometric center at 90 min 2.5 vs. 1.0 (placebo)], and increased pain perception during colonic distension. We conclude that neostigmine has more prominent colonic motor and sensory effects than bethanechol. Moreover, neostigmine induces coordinated colonic propulsion, perhaps by stimulating muscarinic M(1) receptors in the myenteric plexus.     

Rectal and colonic distension elicit viscerovisceral reflexes in humans

Colonic transit is slowed in patients with disordered rectal evacuation, but the mechanism of this phenomenon is unclear. Our objective was to investigate rectocolonic inhibitory reflexes in humans to provide potential insight into patients with obstructed defecation. In 30 healthy subjects, a barostat-manometric assembly recorded colonic tone and phasic activity in the descending colon during rectal distension and recorded rectal tone during colonic distension. Phasic distensions were 8, 16, and 32 mmHg above balloon operating pressure, and staircase inflations were comprised of balloon inflation then deflation in 2-mmHg increments at 30-s intervals from 0 to 36 mmHg. Colonic balloon volumes increased to a similar extent during phasic rectal distensions 8, 16, and 32 mmHg above operating pressure, reflecting reduced colonic tone; balloon volumes also increased and phasic pressure activity decreased during staircase rectal distensions. In contrast, rectal balloon volume declined, reflecting increased tone during phasic and staircase colonic distensions. Thus rectal distension inhibited colonic motor activity, indicative of a viscerovisceral inhibitory reflex.     

Regional Enteritis: Disease Patterns and Medical Management

The clinical picture of regional enteritis was reviewed in 98 cases collected from five hospitals in the City of Edmonton. There was no apparent racial prevalence, although only one case was reported among Indians and Eskimos. More than one-half had their onset between the ages of 11 and 30 years. Men were more commonly affected than women. The onset in 44 patients was acute and closely mimicked acute appendicitis. Twenty-eight patients had had abdominal surgery prior to the onset of symptoms. Major symptoms were abdominal pain, diarrhea and weight loss. Abdominal tenderness, fever and abdominal mass were the most consistent physical signs. The most valuable diagnostic procedure was radiological examination of the bowel. Complications were largely confined to the gastrointestinal tract. In the majority of cases, surgery was the ultimate form of therapy.     

Surgical treatment of idiopathic megacolon]

The authors discuss own experience in diagnosis and surgical treatment of 32 patients with idiopathic megacolon. Three surgical techniques were compared: 1) partial excision of the colon, 2) nearly complete excision of the colon with cecum-rectal anastomosis, and 3) total colectomy with ileorectal anastomosis. Basing on the authors' own experience and available literature the third approach is recommended as the most appropriate in the treatment of the persistent, chronic constipation accompanying idiopathic megacolon.     

Anesthetic management for instrumentation of the pregnant rhesus monkey

The anesthetic procedures used and the responses observed during maternal instrumentation on 38 pregnant rhesus monkeys (Macaca mulatta) during the second half of gestation are reported. A laparotomy with maternal instrumentation was performed in all animals. Anesthesia was induced with ketamine and maintained with halothane. Two animals delivered within five days of anesthesia and surgery and were unable to undergo experimentation. The remaining 36 animals underwent successful experimentation. Dysrhythmias, hypotension, and hypothermia were identified as complications of anesthesia.     

High body mass alters colonic sensory-motor function and transit in humans

There is increased prevalence of abdominal pain and diarrhea and decreased gastric sensation with increased body mass index (BMI). Our hypothesis is that increased BMI is associated with increased colonic motility and sensation. The study aim was to assess effect of BMI on colonic sensory and motor functions and transit. We used a database of colonic tone, compliance, and perception of distensions measured by intracolonic, barostat-controlled balloon, and gastrointestinal transit was measured by validated scintigraphy in healthy obese and nonobese subjects. Regression analysis was applied to assess the association of BMI with colonic sensory and motor functions. We included adjustments for sex differences, age, height, balloon volumes during distension, and psychological stress. Among 165 participants (87 women, 78 men), increased BMI was associated with decreased colonic compliance (P < 0.006, adjusted), decreased pain rating during distensions (P = 0.02, adjusted), and a higher threshold for pain (P = 0.042, adjusted). Sensation for gas, colonic tone, and contraction after meal ingestion were not significantly associated with BMI. Transit was assessed in 72 participants (41 women, 31 men); colonic transit was faster with BMI >30 kg/m(2) (P = 0.003 unadjusted, P = 0.08 adjusted for gender). In conclusion, BMI >25 kg/m(2) is associated with decreased colonic compliance and pain sensation; colonic transit is accelerated particularly with BMI >30 kg/m(2) in women. These data suggest that colonic dysfunction may contribute to diarrhea, but the cause of increased abdominal pain in obesity is not explained by the studies of colonic sensation and requires further study of afferent, spinal, and central mechanisms.