The use of medicinal cannabis has a long history dating back thousands of years. Recent discoveries have shed light on its mechanism of action with the identification of cannabinoid receptors and endocannabinoids, which make up the body\'s endocannabinoid system. Cannabinoid receptors, particularly the cannabinoid 1 and 2 receptors, play a crucial role in modulating the gut-brain axis and serve as potential therapeutic targets for gastrointestinal motility and inflammatory disorders. With increasing legalization of cannabis and a rising number of users, understanding the effects of cannabis on gut motility is essential for nuclear medicine providers. Although tetrahydrocannabinol, the principal psychoactive constituent of cannabis, may decrease gut motility in experimental settings, it appears to paradoxically improve symptoms in gastroparesis. Treatment effects are difficult to measure given the large number of variables that could significantly alter outcomes, such as cannabinoid type, potency, and route of intake. Another consideration is the highly personalized gut microbiome, which directly interacts with the endocannabinoid system. Further research is required to delineate these multifaceted, complex cannabinoid interactions. The goal of this article is to explore the knowns and unknowns of the impact of cannabis on the alimentary system.

BACKGROUND: Hyperkalemia is common among end-stage renal disease (ESRD) patients, and consequently contributes to an increased risk of cardiac arrhythmia. Senna glycoside may decrease colonic transit time and potassium colonic reabsorption.
METHODS: Patients on hemodialysis were randomized to receive either oral senna glycoside (n = 37) or control (n = 36) for 8 weeks. The primary outcomes were predialysis serum potassium and prevalence of hyperkalemia.
RESULTS: At the end of the study, significantly reduced serum potassium concentrations were observed in the senna glycoside compared with the control (-0.32 [95%CI -0.43, -0.04] vs. -0.02 [95%CI -0.12, 0.05] mEq/L, p < 0.001, respectively). The prevalence of hyperkalemia during the study occurred at 13.8% in the control and 5.4% in the senna glycoside (p = 0.309). No serious adverse events were observed.
CONCLUSIONS: Among patients with ESRD on hemodialysis, senna glycoside significantly decreases serum potassium level. Senna glycoside is a safe and possibly effective alternative treatment for hyperkalemia in ESRD.

This review focuses on the role of magnetic resonance imaging (MRI) in the evaluation of the gastrointestinal tract (GI MRI), analyzing the major technical advances achieved in this field, such as diffusion-weighted imaging, molecular imaging, motility studies, and artificial intelligence. Today, MRI performed with the more advanced imaging techniques allows accurate assessment of many bowel diseases, particularly inflammatory bowel disease and rectal cancer; in most of these diseases, MRI is invaluable for diagnosis, staging, and disease monitoring under treatment. Several MRI parameters are currently considered activity biomarkers for inflammation and neoplastic disease. Furthermore, in younger patients with acute or chronic GI disease, MRI can be safely used for short-term follow-up studies in many critical clinical situations because it is radiation-free. MRI assessment of functional gastro-esophageal and small bowel disorders is still in its infancy but very promising, while it is well established and widely used for dynamic assessment of anorectal and pelvic floor dysfunction; MRI motility biomarkers have also been described. There are still some limitations to GI MRI related to high cost and limited accessibility. However, technical advances are expected, such as faster sequences, more specific intestinal contrast agents, AI analysis of MRI data, and possibly increased accessibility to GI MRI studies. Clinical interest in the evaluation of bowel disease using MRI is already very high, but is expected to increase significantly in the coming years.

OBJECTIVE: To assess the effect of postoperative gum chewing on gastrointestinal function in women following laparoscopic gynecological surgery for benign indications.
METHODS: We screened 5 major databases (Medline, Scopus, Google Scholar, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov) from inception till February 2023.
METHODS: No language restrictions were applied. We included randomized controlled trials comparing the postoperative bowel function between patients who chewed and patients who did not chew gum postoperatively after laparoscopic gynecological procedures for benign indications.
RESULTS: Data from 5 studies on 670 patients were extracted and analyzed by 3 independent reviewers. Meta-analysis was performed with RevMan 5.4 software (Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2020), with mean differences (MDs), pooled risk ratios, and random-effects model. Postoperative gum chewing significantly reduced the time to first bowel sounds and the time to first passage of flatus (MD -2.58 hours 95% confidence interval (CI) -4.12 to -1.04 p = .001 and MD -3.97 hours 95% CI -6.26 to -1.68 p <.001, respectively). The time to first defecation, the time to first postoperative patients\' mobilization, the length of hospital stay, and the risk of postoperative bowel obstruction showed no statistically significant difference between the 2 groups. When subgroup analysis was performed according to the type of the laparoscopic procedure, it failed to reveal a positive impact of postoperative gum chewing in both the times to first passage of flatus and first defecation following laparoscopic hysterectomies (MD -5.35 hours 95% CI -10.93 to 0.23 p = .06 and MD -15.93 hours 95% CI -40.13 to 8.28 p = .20, respectively).
CONCLUSIONS: The results of the present meta-analysis support that postoperative gum chewing following laparoscopic gynecological procedures seems to have a positive effect on the early mobilization of the gastrointestinal tract. However, these results should be interpreted with caution due to the small number of the included randomized controlled clinical trials.

BACKGROUND: Magnetic resonance imaging (MRI) tagging techniques have been applied to the GI tract to assess bowel contractions and content mixing. We aimed to evaluate the dependence of a tagging measurement (for assessing chyme mixing) on inter-observer variability in both the ascending colon (AC) and descending colon (DC) and to investigate the temporal variation and hence reliability of the colonic tagging technique by acquiring multiple measurements over time on healthy participants.
METHODS: Two independent datasets of healthy adults were used for the retrospective inter-observer variability (Study 1: 13 datasets and Study 2: 31 datasets), and ten participants were scanned for the prospective temporal variation study following a 1 L mannitol oral preparation. All colonic tagging data were acquired on 3 T MRI scanners. The mean and the standard deviation (SD) maps were generated pixel-by-pixel using custom-written software in MATLAB. The colonic regions of interest were defined using MIPAV software. Bland-Altman plots and scatter plots were used for the inter-observer variability. The mean and SD of all repeated measures for each subject were calculated along with a one-way ANOVA to test for variations with time.
RESULTS: Scatter plots and Bland-Altman plots showed a large range of data with low variation and small limits of agreements (<5% CoV). The intraclass correlation coefficient of inter-rater reliability was excellent and 0.97 or above for the AC and DC measurements for both datasets. The temporal variation study shows that there was no significant difference found between the multiple measures with time (p = 0.53, one-way repeated measures ANOVA test).
CONCLUSIONS: MRI tagging technique can provide an assessment of colonic chyme mixing. The inter-observer study data showed high inter-rater agreement. The temporal variation study showed some individual variations with time suggesting multiple measurements may be needed to increase accuracy.

OBJECTIVE: To investigate the effect of ramosetron after gynecological laparoscopic surgery on the recovery of bowel function.
METHODS: A prospective randomized controlled trial conducted at Kyung Hee University hospital, South Korea, from August 2016 to September 2017. Patients were randomized to receive either 10 mg dexamethasone before induction of anesthesia (control group C), followed by intravenous administration of patient-controlled analgesia (IV-PCA) or 2 ml normal saline before induction of anesthesia and 0.6 mg ramosetron (study group R) administered with IV-PCA.
RESULTS: A total of 88 patients were enrolled. Times to first flatus (group C 23.98 ± 6.31 vs. group R 27.14 ± 9.56 h; P = 0.148) and first defecation (group C 36.16 ± 16.04 vs. group R 43.41 ± 20.01 h; P = 0.138) showed no statistically significant differences. No significant differences were observed in the frequency of postoperative nausea and vomiting (PONV) and demand for additional analgesics. Multiple linear regression for analysis of factors affecting time to first flatus revealed no significant results.
CONCLUSIONS: Ramosetron did not delay bowel movement recovery after gynecologic laparoscopic surgery and was as effective as dexamethasone in regulating PONV. Ramosetron can be used with IV-PCA without concerns about delay in recovery of bowel function. ClinicalTrials.gov registration number: NCT02849483.

BACKGROUND: Recently, aging in patients with severe motor and intellectual disabilities (SMID) has been causing serious problems. There have been few reports about treatment for tumors in patients with SMID.
METHODS: The treatments performed for tumors of 12 SMID patients were examined.
RESULTS: Blood tests and ultrasonography were useful in screening. With regard to treatment, the surgery for SMID patients was performed in the same manner as in healthy cases, and the results were generally satisfactory, without major complications. Typically, the patients were diagnosed in advanced stages; many metachronous double cancers were observed.
CONCLUSIONS: We reported a tumor therapy to the patients with SMID. Our therapy provides satisfactory results for patients with SMID and their families. Further studies are required to clarify the clinical significance of the screening test and the tumor operative method for the patients with SMID.

Neuronal nitric oxide synthase (nNOS) has various roles as a neurotransmitter. However, studies to date have produced insufficient data to fully support the correlation between nNOS and bowel motility. This study aimed to investigate the correlation between nNOS expression and gastrointestinal (GI) tract motility using a stress-induced neonatal maternal separation (NMS) mouse model. In this study, we generated a genetically modified mouse with the HiBiT sequence knock-in into the nNOS gene using CRISPR/Cas9 for analyzing accurate nNOS expression. nNOS expression was measured in the stomach, small intestine, large intestine, adrenal gland, and hypothalamus tissues after establishing the NMS model. The NMS model exhibited a significant increase in nNOS expression in large intestine, adrenal gland, and hypothalamus. Moreover, a significant positive correlation was observed between whole gastrointestinal transit time and the expression level of nNOS. We reasoned that NMS induced chronic stress and consequent nNOS activation in the hypothalamic-pituitary-adrenal (HPA) axis, and led to an excessive increase in intestinal motility in the lower GI tract. These results demonstrated that HiBiT is a sensitive and valuable tool for analyzing in vivo gene activation, and nNOS could be a biomarker of the HPA axis-linked lower intestinal tract dysfunction.

BACKGROUND: Despite constipation being a common clinical condition in older adults, the clinical relevance of constipation related to frailty is less studied. Hence, we aimed to investigate the association between chronic constipation (CC) and frailty in older adults.
METHODS: This is a cross-sectional analysis of a population-based, prospective cohort study of 1278 community-dwelling older adults in South Korea. We used the Rome criteria to identify patients with irritable bowel syndrome with predominant constipation (IBS-C) and functional constipation (FC). We investigated whether participants consistent with the criteria for IBS-C and FC had CC. Frailty was assessed using the Cardiovascular Health Study (CHS) frailty phenotype.
RESULTS: In the study population with a mean age of 75.3 ± 6.3 years, 136 (10.7%) had CC. The participants with CC were older, had higher medication burdens, and had worse physical performances compared to those without CC (All P < .05). By association analysis, the prevalence of CC was associated with frailty by the CHS criteria (P < .001). The CHS frailty score was associated with the presence of CC by the univariate logistic regression analysis and the multivariate analysis adjusted for age, sex, and multimorbidity.
CONCLUSIONS: Frailty was associated with CC in community-dwelling older people, suggesting that constipation should be considered as an important geriatric syndrome in clinical practice concerning frail older adults.

Hirschsprung\'s disease (HSCR) is a common congenital defect. It occurs when bowel colonization by neural crest-derived enteric nervous system (ENS) precursors is incomplete during the first trimester of pregnancy. Several sources of candidate cells have been previously studied for their capacity to regenerate the ENS, including enteric neural crest stem cells (En-NCSCs) derived from native intestine or those simulated from human pluripotent stem cells (hPSCs). However, it is not yet known whether the native NCSCs other than En-NCSCs would have the potential of regenerating functional enteric neurons and producing neuron dependent motility under the intestinal environment. The present study was designed to determine whether premigratory NCSCs (pNCSCs), as a type of the nonenteric NCSCs, could form enteric neurons and mediate the motility. pNCSCs were firstly transplanted into the colon of adult mice, and were found to survive, migrate, differentiate into enteric neurons, and successfully integrate into the adult mouse colon. When the mixture of pNCSCs and human intestinal organoids was implanted into the subrenal capsule of nude mice and grown into the mature tissue-engineered intestine (TEI), the pNCSCs-derived neurons mediated neuron-dependent peristalsis of TEI. These results show that the pNCSCs that were previously assumed to not be induced by intestinal environment or cues can innervate the intestine and establish neuron-dependent motility. Future cell candidates for ENS regeneration may include nonenteric NCSCs.