Constipation: Infrequent or difficult evacuation of FECES. These symptoms are associated with a variety of causes, including low DIETARY FIBER intake, emotional or nervous disturbances, systemic and structural disorders, drug-induced aggravation, and infections.Laxatives: Agents that produce a soft formed stool, and relax and loosen the bowels, typically used over a protracted period, to relieve CONSTIPATION.Defecation: The normal process of elimination of fecal material from the RECTUM.Cathartics: Agents that are used to stimulate evacuation of the bowels.Gastrointestinal Transit: Passage of food (sometimes in the form of a test meal) through the gastrointestinal tract as measured in minutes or hours. The rate of passage through the intestine is an indicator of small bowel function.Fecal Impaction: Formation of a firm impassable mass of stool in the RECTUM or distal COLON.Encopresis: Incontinence of feces not due to organic defect or illness.Defecography: Radiographic examination of the process of defecation after the instillation of a CONTRAST MEDIA into the rectum.Irritable Bowel Syndrome: A disorder with chronic or recurrent colonic symptoms without a clearcut etiology. This condition is characterized by chronic or recurrent ABDOMINAL PAIN, bloating, MUCUS in FECES, and an erratic disturbance of DEFECATION.Fecal Incontinence: Failure of voluntary control of the anal sphincters, with involuntary passage of feces and flatus.Rectum: The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.Gastrointestinal Motility: The motor activity of the GASTROINTESTINAL TRACT.Senna Extract: Preparations of Cassia senna and C. angustifolia (see SENNA PLANT). They contain sennosides, which are anthraquinone type CATHARTICS and are used in many different preparations as laxatives.Megacolon: Dilatation of the COLON, often to alarming dimensions. There are various types of megacolon including congenital megacolon in HIRSCHSPRUNG DISEASE, idiopathic megacolon in CONSTIPATION, and TOXIC MEGACOLON.Colonic Diseases, Functional: Chronic or recurrent colonic disorders without an identifiable structural or biochemical explanation. The widely recognized IRRITABLE BOWEL SYNDROME falls into this category.Anal Canal: The terminal segment of the LARGE INTESTINE, beginning from the ampulla of the RECTUM and ending at the anus.Abdominal Pain: Sensation of discomfort, distress, or agony in the abdominal region.Biofeedback, Psychology: The therapy technique of providing the status of one's own AUTONOMIC NERVOUS SYSTEM function (e.g., skin temperature, heartbeats, brain waves) as visual or auditory feedback in order to self-control related conditions (e.g., hypertension, migraine headaches).Manometry: Measurement of the pressure or tension of liquids or gases with a manometer.Gastrointestinal Agents: Drugs used for their effects on the gastrointestinal system, as to control gastric acidity, regulate gastrointestinal motility and water flow, and improve digestion.Loperamide: One of the long-acting synthetic ANTIDIARRHEALS; it is not significantly absorbed from the gut, and has no effect on the adrenergic system or central nervous system, but may antagonize histamine and interfere with acetylcholine release locally.Toilet Training: Conditioning to defecate and urinate in culturally acceptable places.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Rectal Diseases: Pathological developments in the RECTUM region of the large intestine (INTESTINE, LARGE).Colon: The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.Serotonin 5-HT4 Receptor Agonists: Endogenous compounds and drugs that specifically stimulate SEROTONIN 5-HT4 RECEPTORS.Enema: A solution or compound that is introduced into the RECTUM with the purpose of cleansing the COLON or for diagnostic procedures.Radiography, Abdominal: Radiographic visualization of the body between the thorax and the pelvis, i.e., within the peritoneal cavity.Pelvic Floor: Soft tissue formed mainly by the pelvic diaphragm, which is composed of the two levator ani and two coccygeus muscles. The pelvic diaphragm lies just below the pelvic aperture (outlet) and separates the pelvic cavity from the PERINEUM. It extends between the PUBIC BONE anteriorly and the COCCYX posteriorly.Lactulose: A synthetic disaccharide used in the treatment of constipation and hepatic encephalopathy. It has also been used in the diagnosis of gastrointestinal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p887)Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.Gastrointestinal Diseases: Diseases in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.Hirschsprung Disease: Congenital MEGACOLON resulting from the absence of ganglion cells (aganglionosis) in a distal segment of the LARGE INTESTINE. The aganglionic segment is permanently contracted thus causing dilatation proximal to it. In most cases, the aganglionic segment is within the RECTUM and SIGMOID COLON.Rectocele: Herniation of the RECTUM into the VAGINA.Rectal Prolapse: Protrusion of the rectal mucous membrane through the anus. There are various degrees: incomplete with no displacement of the anal sphincter muscle; complete with displacement of the anal sphincter muscle; complete with no displacement of the anal sphincter muscle but with herniation of the bowel; and internal complete with rectosigmoid or upper rectum intussusception into the lower rectum.Alprostadil: A potent vasodilator agent that increases peripheral blood flow.Bisacodyl: A diphenylmethane stimulant laxative used for the treatment of CONSTIPATION and for bowel evacuation. (From Martindale, The Extra Pharmacopoeia, 30th ed, p871)Diagnostic Techniques, Digestive System: Methods and procedures for the diagnosis of diseases or dysfunction of the digestive system or its organs or demonstration of their physiological processes.Benzofurans: Compounds that contain a BENZENE ring fused to a furan ring.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Thymelaeaceae: A plant family of the order Myrtales, subclass Rosidae, class Magnoliopsida. They are mainly trees and shrubs. Many members contain mucilage and COUMARINS.Dietary Fiber: The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.Neurogenic Bowel: Loss or absence of normal intestinal function due to nerve damage or birth defects. It is characterized by the inability to control the elimination of stool from the body.Psyllium: Dried, ripe seeds of PLANTAGO PSYLLIUM; PLANTAGO INDICA; and PLANTAGO OVATA. Plantain seeds swell in water and are used as demulcents and bulk laxatives.Digestive System Surgical Procedures: Surgery performed on the digestive system or its parts.Actinidia: A plant species of the family ACTINIDIACEAE, order Theales.Colonic Diseases: Pathological processes in the COLON region of the large intestine (INTESTINE, LARGE).Magnesium Oxide: Magnesium oxide (MgO). An inorganic compound that occurs in nature as the mineral periclase. In aqueous media combines quickly with water to form magnesium hydroxide. It is used as an antacid and mild laxative and has many nonmedicinal uses.Hemorrhoids: Swollen veins in the lower part of the RECTUM or ANUS. Hemorrhoids can be inside the anus (internal), under the skin around the anus (external), or protruding from inside to outside of the anus. People with hemorrhoids may or may not exhibit symptoms which include bleeding, itching, and pain.Antidiarrheals: Miscellaneous agents found useful in the symptomatic treatment of diarrhea. They have no effect on the agent(s) that cause diarrhea, but merely alleviate the condition.Ileus: A condition caused by the lack of intestinal PERISTALSIS or INTESTINAL MOTILITY without any mechanical obstruction. This interference of the flow of INTESTINAL CONTENTS often leads to INTESTINAL OBSTRUCTION. Ileus may be classified into postoperative, inflammatory, metabolic, neurogenic, and drug-induced.Dioctyl Sulfosuccinic Acid: All-purpose surfactant, wetting agent, and solubilizer used in the drug, cosmetics, and food industries. It has also been used in laxatives and as cerumenolytics. It is usually administered as either the calcium, potassium, or sodium salt.