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Alimentary Pharmacology & Therapeutics Jun 2024The lower gastrointestinal (GI) tract, formed from the midgut and hindgut, encompasses the colon, rectum and anal canal.
BACKGROUND
The lower gastrointestinal (GI) tract, formed from the midgut and hindgut, encompasses the colon, rectum and anal canal.
AIM
The aim of this review is to provide an overview of the anatomy and physiology of the lower GI tract.
METHODS
Literature review on anatomy and physiology of the lower GI tract, including normal motility and phases of defecation. It derives its blood supply from the superior and inferior mesenteric arteries while it is innervated by the extrinsic autonomic (the thoracolumbar and sacral nerves) and the intrinsic enteric nervous system. The colon has four layers: mucosa, submucosa, muscularis externa and serosa. The anal canal ends in the internal and external anal sphincters (EASs) involved in continence and defecation. The lower GI tract is predominantly involved in digestion, absorption, defecation and protection. Defecation is a complex process that requires inter-neural (enteric and autonomic nervous systems), neurohormonal and neuromuscular coordination. It has four phases which include basal, pre-expulsive, expulsive and end phase. High-propagating contractions in the colon propel stool to the rectum leading to rectal distention and the recruitment of the recto-anal inhibitory reflex. Once able, the EAS, under full conscious control, is then relaxed allowing stool to be evacuated. Other defecation reflexes include the gastrocolic, gastroileal and coloanal reflexes.
CONCLUSIONS
Recent advances provide novel techniques to investigate motility patterns including high-resolution manometry protocols with automated assessments, magnetic resonance imaging techniques for defecography, wireless motility capsules and fecobionics.
PubMed: 38924125
DOI: 10.1111/apt.17900 -
Gastroenterologia Y Hepatologia Jun 2024Defecation disorders can occur as a consequence of functional or structural anorectal dysfunctions during voiding. The aims of this study is to assess the prevalence of...
BACKGROUND/AIMS
Defecation disorders can occur as a consequence of functional or structural anorectal dysfunctions during voiding. The aims of this study is to assess the prevalence of structural (SDD) vs functional (FDD) defecation disorders among patients with clinical complaints of obstructive defecation (OD) and their relationship with patients' expulsive capacity.
PATIENTS AND METHODS
Retrospective study of 588 patients with OD studied between 2012-2020 with evacuation defecography (ED), and anorectal manometry (ARM) in a subgroup of 294.
RESULTS
90.3% patients were women, age was 58.5±12.4 years. Most (83.7%) had SDD (43.7% rectocele, 45.3% prolapse, 19.3% enterocele, and 8.5% megarectum), all SDD being more prevalent in women except for megarectum. Functional assessments showed: a) absence of rectification of anorectal angle in 51% of patients and poor pelvic descent in 31.6% at ED; and b) dyssynergic defecation in 89.9%, hypertonic IAS in 44%, and 33.3% rectal hyposensitivity, at ARM. Overall, 46.4% of patients were categorised as pure SDD, 37.3% a combination of SDD+FDD, and 16.3% as having pure FDD. Rectal emptying was impaired in 66.2% of SDD, 71.3% of FDD and in 78% of patients with both (p=0.017).
CONCLUSIONS
There was a high prevalence of SDD in middle-aged women with complaints of OD. Incomplete rectal emptying was more prevalent in FDD than in SDD although FDD and SDD frequently coexist. We recommend a stepwise therapeutic approach always starting with therapy directed to improve FDD and relaxation of striated pelvic floor muscles.
PubMed: 38857752
DOI: 10.1016/j.gastrohep.2024.502219 -
Pediatric Surgery International Dec 2023To investigate the correlation between postoperative feeding intolerance and defecation, with a view to carrying out prognostic assessment and timely intervention for...
PURPOSE
To investigate the correlation between postoperative feeding intolerance and defecation, with a view to carrying out prognostic assessment and timely intervention for the recovery of postoperative gastrointestinal function.
METHODS
The 114 neonates with congenital intestinal atresia who underwent primary anastomosis admitted to Shenzhen Children's Hospital from January 2014 to December 2022 were studied, and the patients' basic information, intraoperative conditions, postoperative feeding and defecation, and hospitalization time were retrospectively analyzed.
RESULTS
The risk factors for feeding intolerance after primary anastomosis for intestinal atresia are the gestational days, the time of the first postoperative defecations, the number of defecations on the previous day and the average number of defecations before feeding.
CONCLUSION
The incidence of postoperative feeding intolerance is higher in preterm infants, and pediatricians can decide the timing of breastfeeding on the basis of the patients' defecation. The focus on accurate defecation may be more meaningful in determining and predicting postoperative feeding intolerance in the infants.
Topics: Infant; Child; Female; Infant, Newborn; Humans; Infant, Premature; Defecation; Intestinal Atresia; Retrospective Studies; Infant, Newborn, Diseases; Anastomosis, Surgical
PubMed: 38133659
DOI: 10.1007/s00383-023-05603-x -
Acta Obstetricia Et Gynecologica... Aug 2023Obstetric anal sphincter injury is an important risk factor for postpartum fecal incontinence but few studies have reported fecal incontinence occurring, even during...
INTRODUCTION
Obstetric anal sphincter injury is an important risk factor for postpartum fecal incontinence but few studies have reported fecal incontinence occurring, even during pregnancy. The first objective of this study was to examine the prevalence of fecal incontinence, obstructed defecation and vaginal bulging early and late in pregnancy and postpartum. The second objective was to assess the association between symptoms in pregnancy, delivery characteristics, and bowel and vaginal bulging symptoms at 1 year postpartum.
MATERIAL AND METHODS
This prospective cohort study was conducted between October 2014 and October 2017, including 898 nulliparous women enrolled with the maternity healthcare service in Örebro County, Sweden. The women responded to questionnaires regarding pelvic floor dysfunction in early and late pregnancy and at 8 weeks and 1 year postpartum. The data were analyzed using random effect logistic models estimating odds ratios (ORs) and generalized linear models estimating relative risks, with 95% confidence intervals (CIs).
RESULTS
At 1 year postpartum, the prevalence of fecal incontinence, obstructed defecation and vaginal bulging was 6% (40/694), 28% (197/699) and 8% (56/695), respectively. Among women with vaginal delivery, the risk of fecal incontinence and vaginal bulging increased significantly both in late pregnancy, with ORs of 3.4 (95% CI 1.5-7.7) and 3.6 (95% CI 1.6-8.1), respectively, and at 1 year postpartum, with ORs of 5.0 (95% CI 2.1-11.5) and 8.3 (95% CI 3.8-18.1), respectively, compared with early pregnancy. Among all women, factors associated with increased prevalence of fecal incontinence 1 year postpartum were fecal incontinence during pregnancy (adjusted relative risk [aRR] 7.4; 95% CI 4.1-13.3), obstructed defecation during pregnancy (aRR 2.0; 95% CI 1.1-3.9) and concurrent obstructed defecation (aRR 2.4; 95% CI 1.3-4.5).
CONCLUSIONS
This prospective study shows an increased risk of fecal incontinence by late pregnancy, suggesting that the pregnancy itself may be involved in the development of postpartum fecal incontinence. Obstructed defecation during pregnancy and postpartum was found to be associated with increased risk of fecal incontinence postpartum, indicating that postpartum fecal incontinence may be a result of incomplete bowel emptying.
Topics: Pregnancy; Female; Humans; Fecal Incontinence; Prospective Studies; Pelvic Floor; Delivery, Obstetric; Gravidity; Surveys and Questionnaires
PubMed: 37338103
DOI: 10.1111/aogs.14614 -
Annual Review of Animal Biosciences Feb 2024The bare-nosed wombat is an iconic Australian fauna with remarkable biological characteristics and mythology. This solitary, muscular, fossorial, herbivorous marsupial... (Review)
Review
The bare-nosed wombat is an iconic Australian fauna with remarkable biological characteristics and mythology. This solitary, muscular, fossorial, herbivorous marsupial from southeast Australia has continent and continental island subspeciation. Vombatiformes also contains hairy-nosed wombats ( spp.); koala (); and extinct megafauna, (giant wombat), , and (marsupial lion). Culturally important to Aboriginal people, bare-nosed wombats engineer ecosystems through digging, grazing, and defecation. Olfaction and cubic fecal aggregations appear critical for communication, including identity, courtship, and mating. Though among the largest fossorial herbivores, they have a nutrient-poor diet, a home range up to an order of magnitude smaller than expected, and a metabolism among the lowest extreme for mammals >10 kg. Metabolic depression may confer advantages over resource competitors and fossorial lifestyle protection from predators, fires, and climatic extremes. Bare-nosed wombats are loved and persecuted by European colonists. Recent population increases may reflect softening attitudes toward, and greater protections of, bare-nosed wombats.
Topics: Animals; Ecosystem; Australia; Marsupialia; Biology
PubMed: 37738454
DOI: 10.1146/annurev-animal-021022-042133 -
Journal of Ethnopharmacology Nov 2023Psydrax schimperianus (A. Rich.) Bridson. roots are used for the treatment of diarrhea in West Arsi zone, Ethiopia.
ETHNOPHARMACOLOGICAL RELEVANCE
Psydrax schimperianus (A. Rich.) Bridson. roots are used for the treatment of diarrhea in West Arsi zone, Ethiopia.
AIM OF THE STUDY
This study aimed to investigate the in vivo antidiarrheal activity of crude extract and coumarins isolated from the roots of Psydrax schimperianus to provide a pharmacological basis for its traditional use as an antidiarrheal agent in Ethiopia.
MATERIALS AND METHODS
The crude root extract of P. schimperianus was tested in vivo for antidiarrheal efficacy in mice utilizing castor oil-induced diarrhea, gastrointestinal transit time, and enteropooling models at doses of 100, 200, and 400 mg/kg. Phytochemical investigation of the crude root extract led to the isolation of two coumarins, isoscopoletin, and scoparone. Isoscopoletin and scoparone were evaluated for antidiarrheal activity against castor oil-induced diarrhea model at 10 mg/kg and 20 mg/kg doses.
RESULTS
The crude root extract of P. schimperianus, at doses of 100, 200, and 400 mg/kg, inhibited defecation by 37.5%, 46.2%, and 61.2%, respectively. At a dose of 20 mg/kg, scoparone and isoscopoletin reduced defecation by 61.2% and 66.6%, respectively.
CONCLUSION
The study warrants further investigation of isoscopoletin and scoparone towards development as a novel treatment for diarrheal diseases.
Topics: Mice; Animals; Antidiarrheals; Castor Oil; Plant Extracts; Diarrhea; Coumarins
PubMed: 37301303
DOI: 10.1016/j.jep.2023.116705 -
The Lancet. Oncology Mar 2024The faecal immunochemical test (FIT) is widely employed for colorectal cancer screening. However, its sensitivity for advanced precursor lesions remains suboptimal. The...
BACKGROUND
The faecal immunochemical test (FIT) is widely employed for colorectal cancer screening. However, its sensitivity for advanced precursor lesions remains suboptimal. The multitarget FIT (mtFIT), measuring haemoglobin, calprotectin, and serpin family F member 2, has demonstrated enhanced sensitivity for advanced neoplasia, especially advanced adenomas, at equal specificity to FIT. This study aimed to prospectively validate and investigate the clinical utlitity of mtFIT versus FIT in a setting of population-based colorectal cancer screening.
METHODS
Individuals aged 55-75 years and who were eligible for the Dutch national FIT-based colorectal cancer screening programme were invited to submit both a FIT and mtFIT sample collected from the same bowel movement. Positive FIT (47 μg/g haemoglobin cutoff) or mtFIT (based on decision-tree algorithm) led to a colonoscopy referral. The primary outcome was the relative detection rate of mtFIT versus FIT for all advanced neoplasia. Secondary outcomes were the relative detection rates of colorectal cancer, advanced adenoma, and advanced serrated polyps individually and the long-term effect of mtFIT-based versus FIT-based programmatic screening on colorectal cancer incidence, mortality, and cost, determined with microsimulation modelling. The study has been registered in ClinicalTrials.gov, NCT05314309, and is complete.
FINDINGS
Between March 25 and Dec 7, 2022, 35 786 individuals were invited to participate in the study, of whom 15 283 (42·7%) consented, and 13 187 (86·3%) of 15 283 provided both mtFIT and FIT samples with valid results. Of the 13 187 participants, 6637 (50·3%) were male and 6550 (49·7%) were female. mtFIT showed a 9·11% (95% CI 8·62-9·61) positivity rate and 2·27% (95% CI 2·02-2·54) detection rate for advanced neoplasia, compared with a positivity rate of 4·08% (3·75-4·43) and a detection rate of 1·21% (1·03-1·41) for FIT. Detection rates of mtFIT versus FIT were 0·20% (95% CI 0·13-0·29) versus 0·17% (0·11-0·27) for colorectal cancer; 1·64% (1·43-1·87) versus 0·86% (0·72-1·04) for advanced adenoma, and 0·43% (0·33-0·56) versus 0·17% (0·11-0·26) for advanced serrated polyps. Modelling demonstrated that mtFIT-based screening could reduce colorectal cancer incidence by 21% and associated mortality by 18% compared with the current Dutch colorectal cancer screening programme, at feasible costs. Furthermore, at equal positivity rates, mtFIT outperformed FIT in terms of diagnostic yield. At an equally low positivity rate, mtFIT-based screening was predicted to further decrease colorectal cancer incidence by 5% and associated mortality by 4% compared with FIT-based screening.
INTERPRETATION
The higher detection rate of mtFIT for advanced adenoma compared with FIT holds the potential to translate into additional and clinically meaningful long-term colorectal cancer incidence and associated mortality reductions in programmatic colorectal cancer screening.
FUNDING
Stand Up to Cancer, Dutch Cancer Society, Dutch Digestive Foundation, and Health~Holland.
Topics: Humans; Early Detection of Cancer; Defecation; Colorectal Neoplasms; Adenoma; Hemoglobins
PubMed: 38346438
DOI: 10.1016/S1470-2045(23)00651-4 -
The American Journal of Tropical... Jun 2024South Asian children are among the most severely malnourished worldwide. One prominent hypothesis is that open defecation in the local area exposes children to human...
South Asian children are among the most severely malnourished worldwide. One prominent hypothesis is that open defecation in the local area exposes children to human fecal pathogens that can cause diarrhea and malnutrition. Much of the existing research uses district-level measures of open defecation, which could mask important local-area variation. A second hypothesis is that animal fecal matter is a major source of exposure. This analysis tested these dual hypotheses using census data collected from 949 villages in Tamil Nadu, India, and a survey conducted in a random sample of 5,000 households in the same area. The final analytic sample consisted of 2,561 children aged 0-10 years. We estimated the association between the measures of village- and household-level open defecation, household livestock ownership, and child height-for-age Z-scores in a regression framework, controlling for potential confounders. Results revealed that village- and household-level open defecations are negatively associated with child height. There was an estimated difference of approximately 0.5 height-for-age Z-score between children living in villages with no open defecation and children in villages where all households practiced open defecation (P = 0.001) and a 0.2 Z-score difference between children living in households that practiced open defecation and those living in households that did not (P = 0.001). Livestock ownership was not associated with child height. Overall, the findings provide evidence on the centrality of open defecation in explaining persistent child malnutrition in India and the higher risk of exposure to human fecal pathogens compared with animal feces in the south Indian context.
Topics: Humans; India; Animals; Child, Preschool; Livestock; Infant; Male; Female; Nutritional Status; Defecation; Child; Ownership; Feces; Infant, Newborn; Family Characteristics; Diarrhea; Body Height
PubMed: 38688272
DOI: 10.4269/ajtmh.23-0405 -
European Journal of Pediatrics Nov 2023Functional gastrointestinal disorders (FGID) are disorders of gut-brain interactions characterized by chronic recurrent gastrointestinal symptoms and are reported to be...
UNLABELLED
Functional gastrointestinal disorders (FGID) are disorders of gut-brain interactions characterized by chronic recurrent gastrointestinal symptoms and are reported to be more common in obese individuals. The aim of the study was to evaluate FGID in obese children. A total of 405 children (6-18 years) were enrolled in this cross sectional study. The children were divided into two groups according to body mass index (BMI) as < 85th percentile and > 95th percentile. Diagnosis of FGID was based on ROME VI criteria. Demographic and clinical characteristics of the patients were evaluated. FGID and subgroups were determined. The mean age of the children was 12.73 ± 3.17 years; 52% (n = 211) of them was female and 47.9% (n = 194) was male. A total of 50.6% patients had BMI > 95th percentile, and 55.1% of those patients had FGID. The subgroups of FGID, functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group (P < 0.01). Additionally, constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children (P < 0.01).
CONCLUSION
FGID in obese children was found to be increased significantly. Assessment of functional gastrointestinal symptoms in obese children will prevent unnecessary examinations.
WHAT IS KNOWN
• Functional gastrointestinal disorders are reported to be more common in obese individuals.
WHAT IS NEW
• Functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group. • Constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children.
Topics: Humans; Male; Child; Female; Adolescent; Irritable Bowel Syndrome; Cross-Sectional Studies; Pediatric Obesity; Gastrointestinal Diseases; Diarrhea; Abdominal Pain; Surveys and Questionnaires; Constipation
PubMed: 37606702
DOI: 10.1007/s00431-023-05165-z