gastrointestinalkanal

The gastrointestinalkanal, or gastrointestinal tract, is a continuous muscular tube that extends from the mouth to the anus. It serves to ingest, digest, absorb nutrients, and eliminate indigestible remains. In adults its length is commonly estimated at several meters, comprising multiple specialized regions that work together to process food.

The canal begins in the oral cavity, continues through the pharynx and esophagus, and enters the stomach, where mechanical mixing and chemical digestion begin. It then proceeds to the small intestine, consisting of the duodenum, jejunum, and ileum, where most nutrient absorption takes place. The large intestine (cecum, colon, and rectum) absorbs water and electrolytes and forms solid waste for elimination. Accessory organs—the liver, pancreas, and gallbladder—secrete bile and digestive enzymes that enter the lumen via ducts, supporting digestion.

Physiology involves both mechanical processes, such as peristaltic movements, and chemical processes, including enzymatic breakdown of carbohydrates, proteins, and fats. The majority of nutrient absorption occurs in the small intestine, aided by a highly folded mucosa with villi and microvilli. The enteric nervous system coordinates motility and secretion, with modulation from the autonomic nervous system. The gut microbiota, particularly in the colon, plays roles in fermentation, vitamin production, and immune function.

Common concerns affecting the gastrointestinalkanal include gastroesophageal reflux disease, peptic ulcers, inflammatory bowel disease, celiac disease, diverticular disease, and colorectal cancer. Diagnosis and management rely on history, endoscopy, imaging, laboratory tests, and, when needed, surgical intervention.