Bowel

The bowel refers to sections of the digestive tract, primarily the small and large intestines. The small intestine consists of the duodenum, jejunum, and ileum, where most digestion and nutrient absorption occur. The large intestine includes the cecum, colon, and rectum, where water absorption and stool formation take place.

Functions include digestion of food residues, absorption of water and electrolytes, and transit of waste toward elimination. The small intestine provides most nutrient uptake, aided by enzymes and bile; the colon reabsorbs water and electrolytes and hosts gut microbiota that ferment undigested carbohydrates. Peristaltic movements and sphincter control regulate the flow of contents.

Common conditions affecting the bowel include bowel obstruction, inflammatory bowel disease (Crohn disease and ulcerative colitis), irritable bowel syndrome, diverticular disease, and colorectal cancer. Symptoms may involve abdominal pain, changes in bowel habits, bloating, blood in stool, and unintended weight loss. Some conditions require urgent evaluation.

Diagnosis typically combines history, physical examination, laboratory tests, imaging, and endoscopic procedures such as colonoscopy. Treatments depend on the disease and may include dietary adjustments, medications to modulate inflammation or motility, antibiotics for infection, and surgical intervention in selected cases. Preparation for procedures may involve laxatives to cleanse the bowel.