Anorectal physiology

The remit of this review is confined to the experimental scientific works and surgeries based on the Integral Theory paradigm. The video abstract summarizes the anorectal function, how ligaments cause dysfunction and cure of fecal incontinence and obstructed defecation by ligament repair. Anorectal function is reflex and binary, with cortical and peripheral components. The same three oppositely acting reflex muscle forces which open and close the bladder, contract against the pubourethral (PUL) and uterosacral (USL) ligaments: (I) to close the anorectum for continence when the puborectalis muscle (PRM) contracts forwards; (II) to open the anorectum prior to evacuation when the PRM relaxes; (III) to stretch the rectum in opposite directions to support the anorectal stretch receptors "N" to prevent premature activation of the defecation reflex, (fecal urgency)...

Internal anal sphincter achalasia (IASA) is a rare anorectal disorder that presents as chronic refractory constipation in pediatrics. With a poor response to conventional constipation-based therapy, it is often misdiagnosed as other conditions, such as ultra-short-segment Hirschsprung disease. This case report describes a rare case of IASA in an adolescent female, emphasizing the importance of ruling out other differentials, including Hirschsprung disease, via rectal biopsy and thus allowing for earlier targeted therapy to improve lifestyle conditions...

OBJECTIVE: Glucose dependent insulinotropic polypeptide (GIP) is well established as an incretin hormone, boosting glucose-dependent insulin secretion. However, whilst anorectic actions of its sister-incretin glucagon-like peptide-1 (GLP-1) are well established, a physiological role for GIP in appetite regulation is controversial, despite the superior weight loss seen in preclinical models and humans with GLP-1/GIP dual receptor agonists compared with GLP-1R agonism alone. METHODS: We generated a mouse model in which GIP expressing K-cells can be activated through hM3Dq Designer Receptor Activated by Designer Drugs (DREADD, GIP-Dq) to explore physiological actions of intestinally-released GIP...

Nicotine use produces psychoactive effects, and chronic use is associated with physiological and psychological symptoms of addiction. However, chronic nicotine use is known to decrease food intake and body weight gain, suggesting that nicotine also affects central metabolic and appetite regulation. We recently showed that acute nicotine self-administration in nicotine-dependent animals produces a short-term increase in food intake, contrary to its long-term decrease of feeding behavior. As feeding behavior is regulated by complex neural signaling mechanisms, this study aimed to test the hypothesis that nicotine intake in animals exposed to chronic nicotine may increase activation of pro-feeding regions and decrease activation of pro-satiety regions to produce the acute increase in feeding behavior...

Endoanal ultrasound (EAUS) is a valuable imaging modality for the evaluation of anal and perianal pathologies. It provides detailed information about the anatomy and physiology of the anorectal region and has been used in pre-and post-operative settings of anorectal pathologies. EAUS is not only useful in the evaluation of benign pathologies but also in loco-regional staging of anal and rectal tumors. EAUS has several advantages over MRI, including reduced cost, better patient tolerance, and improved scope of application in patients with contraindications to MRI...

OBJECTIVES: Refractory functional constipation is a challenging condition to manage in children. The use of transanal irrigation (TAI) is well reported in children with neurological disorders as well as anorectal malformations but less so in children with functional disorders of defecation. The objective of our study was to evaluate the effectiveness, safety and outcomes of TAI in children with functional constipation. METHODS: PubMed, Scopus and Google Scholar were searched for publications related to the use of TAI in functional constipation...

BACKGROUND/AIMS: It is a common belief that constipated patients have hard feces that contributes to the difficulties defecating. To the best of our knowledge, no studies had been published on controlled evacuation of simulated feces with different consistencies. METHODS: Twelve normal subjects were recruited for studies with the simulated feces device "Fecobionics" of different consistency (silicone shore 0A-40A corresponding to Bristol Stool Form Scale types 2-4)...

Humans and their immune system are confronted with mold-contaminated food and/or mold-contaminated air in daily life and indoor activities. This results in metabolic stress and unspecific disease symptoms. Other studies provided evidence that exposure to mold is associated with the etiology of allergies. Deoxynivalenol (DON) is of great concern due to its frequent occurrence in toxically relevant concentrations. The exposure to this toxin is a permanent health risk for both humans and farm animals because DON cannot be significantly removed during standard milling and processing procedures...

INTRODUCTION: Human development includes lots of physical and emotional changes. The human voice depends on age. Voice production is a complex physiological and acoustic phenomenon that depends on many factors such as structure, hormone level, degree of fatigue or nutrition and hydration of the body, systemic diseases, and emotional state. All these factors can be present in anorexia nervosa (AN), such as excessive weight loss, generated hydro-electrolytic changes, nutritional deficiencies, hormonal disturbances in the function of the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-thyroid axis, the hypothalamic-pituitary-ovarian axis, and emotional distress...

BACKGROUND: Faecal incontinence is a common debilitating condition associated with poor quality of life that generates substantial economic strain on healthcare systems. OBJECTIVES: We aimed to evaluate, in a tertiary referral population presenting with faecal incontinence, the impact of suffering additional disorders of gut-brain interaction (DGBI) on symptom severity, anxiety, depression and quality of life. METHODS: Design: Retrospective cohort study...

Abnormal visceral perception and motor function are often observed in patients with fecal incontinence, evacuation disorders and irritable bowel syndrome. The international anorectal physiology working group has proposed a standardization for anorectal function assessment, where rectal sensitivity testing is performed using an elastic balloon attached to a high-resolution anorectal manometry (HRAM) catheter. Rectal compliance, another component of rectal function evaluation, is a pressure-volume relationship that refers to the rectum's ability to stretch and expand as it receives and holds fecal matter...

BACKGROUND: Chronic constipation (CC) is defined by symptom criteria reflecting heterogenous physiology. However, many patients with CC have significant psychological comorbidities-an alternative definition using a biopsychosocial classification model could be warranted to inform future treatments. We sought to: (1) empirically derive psychological symptom profiles of patients with CC using latent profile analysis and (2) validate these profiles by comparing them on symptom severity, GI-specific anxiety, body mass index (BMI), and anorectal manometry findings...

Incretin-based pharmacotherapies provide novel efficient and safe therapeutic options to curb appetite and produce weight loss in obese patients. Delivered systemically, these molecules produce pleiotropic metabolic benefits, but the target sites mediating their weight-suppressive action are located within the brain. Recent research has increased our understanding of the neural circuits and behavioural mechanisms involved in the anorectic and metabolic consequences of glucagon-like peptide 1 (GLP-1)-based weight loss strategies, yet little is known about how these drugs access their functional targets in the brain to produce sustained weight loss...

Gastrin is an important intragastrointestinal hormone, but reports on its regulation of feeding behavior in fish are still scarce. This study aimed to determine the feeding regulatory function of gastrin in sturgeon. In this study, a gastrin/cholecystokinin-like peptide was identified in the genomes of sturgeon and proved to be gastrin by evolutionary tree analysis. Tissue distribution of gastrin and its receptor, cholecystokinin receptor B (CCKRB), showed that both had high mRNA abundance in the hypothalamus and gastrointestinal tract...

Fecobionics is a novel integrated technology for assessment of anorectal function. It is a defecatory test with simultaneous measurements of pressures, orientation, and device angle (a proxy of the anorectal angle). Furthermore, the latest Fecobionics prototypes measure diameters (shape) using impedance planimetry during evacuation of the device. The simultaneous measurement of multiple variables in the integrated test allows new metrics to be developed including more advanced novel defecation indices, enabling mechanistic insight in the defecation process at an unprecedented level in patients with anorectal disorders including patients suffering from obstructed defecation, fecal incontinence, and low anterior resection syndrome...

BACKGROUND: Rectal cancer is commonly treated by chemoradiation therapy, followed by the low anterior resection anal sphincter-preserving surgery, with a temporary protecting ileostomy. After reversal of the stoma a condition known as low anterior resection syndrome (LARS) can occur characterized by a combination of symptoms such as urgent bowel movements, lack of control over bowel movements, and difficulty fully emptying the bowels. These symptoms have a significant negative impact on the quality of life for individuals who have survived the cancer...

Fecal incontinence (FI) is often underreported and underestimated in men. Our aims were to clarify the causes and the physiological characteristics of FI in men and to underline the differences between etiological and physiological factors in men and women diagnosed with FI. The study cohort encompassed 200 men and 200 women who underwent anatomical and physiological evaluation for FI in a tertiary referral center specializing in pelvic floor disorders. All patients underwent endoanal ultrasound and anorectal manometry...

BACKGROUND: Defecation dysfunction may contribute to chronic constipation (CC), but the impact of obesity on anorectal physiology in CC remains unclear. We aimed to evaluate the relationship between obesity and anorectal function on physiologic testing in patients presenting with CC. METHODS: This was a retrospective cohort study of consecutive adults who underwent high resolution anorectal manometry (HRAM) at a tertiary center for CC. Patient demographics, clinical history, surgical/obstetric history, medications, and HRAM results were reviewed...

PURPOSE: Three subtypes of fecal incontinence (FI) are described in the literature: urge, mixed and passive FI, but the relevance of this classification remains unknown. To our knowledge, no questionnaire has been validated in a general population of patients with FI to classify patients between the different subtypes of FI. The aim of the present study was to validate the Fecal Incontinence Subtype Assessment (FI-SA) questionnaire in a general population of patients with FI. METHODS: All consecutive patients referred to our unit for physiological investigations of anorectal function in case of FI were included...

OBJECTIVES: Nearly half of patients with slow transit constipation (STC) are not completely satisfied with their traditional remedies. We aimed to evaluate the therapeutic value and possible involved mechanism of transcutaneous electrical acustimulation (TEA) at ST36 in patients with STC. MATERIALS AND METHODS: Seventy patients with STC were randomly divided into TEA (n = 35) and sham-TEA (n = 35) to undergo a two-week treatment with TEA at ST36 or sham point...