Szarka, Lawrence A.

AbstractBackgroundColonic pseudo‐obstruction (CPO) is characterized by colonic distention in the absence of mechanical obstruction or toxic megacolon. Concomitant secretory diarrhea (SD) with hypokalemia (SD‐CPO) due to gastrointestinal (GI) loss requires further characterization.AimTo perform a systematic review of SD‐CPO, report a case study, and compare SD‐CPO with classical CPO (C‐CPO).MethodsWe performed a search of MEDLINE, EMBASE, Cochrane, and Scopus for reports based on a priori criteria for CPO, SD and GI loss of potassium. An additional case at Mayo Clinic was included.ResultsNine publications met inclusion criteria, with a total of 14 cases. Six studies had high, three moderate, and our case high methodological quality. Median age was 74 years (66‐97), with 2:1 male/female ratio. Kidney disease was present in 6/14 patients. Diarrhea was described as profuse, watery, or viscous in 10 patients. Median serum, stool, and urine potassium concentrations (mmol/L) were 2.4 (range: 1.9‐3.1), 137 (100‐180), and 17 (8‐40), respectively. Maximal diameter of colon and cecum (median) were 10.2 cm and 10.5 cm, respectively. Conservative therapy alone was effective in five out of 14 patients. Median potassium supplementation was 124 mEq/d (40‐300). Colonic decompression was effective in three out of six patients; one had a total colectomy; three out of 14 had died. The main differences between SD‐CPO and C‐CPO were lower responses to treatments: conservative measures (35.7% vs 73.6%, P=.01), neostigmine (17% vs 89.2%, P<.001), and colonic decompression (50% vs 82.4%, P=.02).ConclusionSD‐CPO is a rare phenotype associated with increased fecal potassium and is more difficult to treat than C‐CPO.

Abstract Background Acetylcholinesterase inhibitors ( ACI s), e.g., neostigmine, are known to increase upper and lower gastrointestinal ( GI ) motility and are used to treat acute colonic pseudoobstruction. However, their effects on gastroduodenal motility in humans are poorly understood. Our hypotheses were that, in patients with suspected GI motility disorders, neostigmine increases gastric and small intestinal motor activity, and these effects are greater in patients with cardiovagal neuropathy, reflecting denervation sensitivity. Methods In this open label study, the effects of neostigmine (1 mg intravenously) on gastroduodenal motor activity recorded with manometry were assessed in 28 patients with a suspected GI motility disorder. Cardiovagal function was assessed with the heart rate response to deep breathing and GI transit by scintigraphy. Key Results The final diagnoses were gastroparesis (6 patients), gastroparesis with intestinal neuropathy (3 patients), intestinal neuropathy or pseudoobstruction (5 patients), functional dyspepsia (6 patients), chronic abdominal pain (3 patients), mechanical small intestinal obstruction (3 patients), and pelvic floor dysfunction (2 patients). Neostigmine increased both antral and intestinal phasic pressure activity ( p < 0.001). Neostigmine increased antral and intestinal pressure activity in 81% and 50% of patients with reduced postprandial antral and intestinal contractile responses to meal, respectively. The antroduodenal pressure response to neostigmine was not higher in patients with cardiovagal dysfunction. Conclusions & Inferences Neostigmine increased antral and intestinal motor activity in patients with hypomotility, including intestinal dysmotility. These responses to neostigmine were not greater in patients with cardiovagal dysfunction. The use of longer‐acting ACI s for treating antroduodenal dysmotility warrant further study.

AbstractBackgroundCurrently, anorectal manometry (ARM), which is used to diagnose defecatory disorders and identify anal weakness in fecal incontinence (FI) is generally conducted in specialized laboratories. Our aims were to compare anorectal functions measured with high‐resolution manometry (HRM) and a novel portable manometry device.MethodsAnal pressures at rest, during squeeze, and simulated evacuation, and rectal sensation were evaluated with portable and HRM in 20 healthy women, 19 women with constipation, and 11 with FI. The relationship between anal pressures measured with portable and HRM was assessed by the concordance correlation coefficient (CCC), Bland Altman test, and paired t‐tests.Key ResultsAnal pressures at rest (CCC 0.45; 95% CI: 0.29, 0.58) and during squeeze (CCC 0.60; 95% CI: 0.46, 0.72) measured with portable and HRM were correlated and inversely associated with the risk of FI. During simulated evacuation, the CCC for rectal pressure (0.62; 95% CI: 0.43, 0.76) was greater than that for anal pressure (CCC 0.22; 95% CI: 0.04, 0.39) and the rectoanal gradient (CCC 0.22; 95% CI: 0.02, 0.41). Rectal sensory thresholds for first sensation, the desire to defecate, and urgency measured by portable and HRM were also significantly correlated between techniques. For several parameters, differences between portable and HRM were statistically significant and the Bland Altman test was positive.Conclusions & InferencesAnorectal pressures and rectal sensation can be conveniently measured by portable manometry and are significantly correlated with high‐resolution manometry.

To compare the effects of the κ-opioid agonist asimadoline and placebo on visceral sensation and gastrointestinal (GI) motor functions in humans, 91 healthy participants were randomized in a double-blind fashion to 0.15, 0.5, or 1.5 mg of asimadoline or placebo orally twice a day for 9 days. We assessed satiation (nutrient drink test), colonic compliance, tone, perception of colonic distension (barostat), and whole gut transit (scintigraphy). Treatment effect was assessed by analysis of covariance. Asimadoline increased nutrient drink intake ( P = 0.03). Asimadoline decreased colonic tone during fasting ( P = 0.03) without affecting postprandial colonic contraction, compliance, or transit. Gas scores in response to colonic distension were decreased with 0.5 mg of asimadoline at low levels (8 mmHg above operating pressure) of distension ( P = 0.04) but not at higher levels of distension. Asimadoline at 1.5 mg increased gas scores at 16 mmHg of distension ( P = 0.03) and pain scores at distensions of 8 and 16 mmHg ( P = 0.003 and 0.03, respectively) but not at higher levels of distension. Further studies of this compound in diseases with altered satiation or visceral sensation are warranted.

AbstractBackgroundChronic gastrointestinal dysmotility greatly impacts the quality of life. Treatment options are limited and generally symptomatic. Neural autoimmunity is an under‐recognized etiology. We evaluated immunotherapy as an aid to diagnosing autoimmune gastrointestinal dysmotility (AGID).MethodsTwenty‐three subjects evaluated at the Mayo Clinic for suspected AGID (August 2006–February 2014) fulfilled the following criteria: (1) prominent symptoms of gastrointestinal dysmotility with abnormalities on scintigraphy–manometry; (2) serological evidence or personal/family history of autoimmune disease; (3) treated by immunotherapy on a trial basis, 6–12 weeks (intravenous immune globulin, 16; or methylprednisolone, 5; or both, 2). Response was defined subjectively (symptomatic improvement) and objectively (gastrointestinal scintigraphy/manometry studies).Key ResultsSymptoms at presentation: constipation, 18/23; nausea or vomiting, 18/23; weight loss, 17/23; bloating, 13/23; and early satiety, 4/23. Thirteen patients had personal/family history of autoimmunity. Sixteen had neural autoantibodies and 19 had extra‐intestinal autonomic testing abnormalities. Cancer was detected in three patients. Preimmunotherapy scintigraphy revealed slowed transit (19/21 evaluated; gastric, 11; small bowel, 12; colonic, 11); manometry studies were abnormal in 7/8. Postimmunotherapy, 17 (74%) had improvement (both symptomatic and scintigraphic, five; symptomatic alone, eight; scintigraphic alone, four). Nine responders re‐evaluated had scintigraphic evidence of improvement. The majority of responders who were re‐evaluated had improvement in autonomic testing (six of seven) or manometry (two of two).Conclusions & InferencesThis proof of principle study illustrates the importance of considering an autoimmune basis for idiopathic gastrointestinal dysmotility and supports the utility of a diagnostic trial of immunotherapy.

Gastroparesis and other types of gastric dysfunction result in substantial morbidity in diabetes patients. The pathophysiology of these disorders is incompletely understood. This article reviews techniques applicable to the assessment of gastric function in diabetes patients, including the measurement of emptying, accommodation, and contractility. Available treatment options are also reviewed, including novel yet unapproved serotonin 5-HT 4 agonist pharmacological treatments, as well as the role of endoscopic, surgical, and device treatments of gastroparesis.