Unit
- Anatomy of the GI tract: The gastrointestinal tract extends from the oral cavity to the anus and includes the esophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, colon, rectum), and anus. Each segment has specialized functions in digestion, absorption, and elimination.
- Role of the small intestine: The jejunum and ileum are responsible for nutrient absorption. The ileum also absorbs vitamin B12 and bile salts. Loss of ileum can lead to dehydration and nutritional deficiencies.
- Colon function: The colon absorbs water and electrolytes, forms stool, and provides storage until defecation. The ascending, transverse, descending, and sigmoid colon each contribute to these processes.
- Stoma creation sites: A stoma is surgically created from a segment of intestine brought to the abdominal surface. The type of stoma depends on which part of the bowel is exteriorized: ileostomy from ileum, colostomy from colon.
- Vascular supply: The mesenteric arteries supply blood to the intestines. Adequate blood flow is crucial for stoma viability; ischemia can lead to necrosis.
- Innervation and motility: The enteric nervous system controls peristalsis and secretion. After stoma surgery, bowel motility may be temporarily altered.
- Common stoma locations: An ileostomy is typically located in the right lower quadrant; a colostomy may be in the left lower quadrant or upper abdomen depending on the segment used.
- Stoma anatomy: The stoma consists of mucosa (red, moist tissue) and a mucocutaneous junction where the mucosa meets the skin. Proper healing at this junction is critical.
- Stoma assessment: Regular assessment of stoma color, size, shape, and output is essential. A healthy stoma appears pink or red, moist, and slightly raised. Changes in color such as pale, dusky, or black indicate ischemia. Output consistency and volume should be monitored to detect dehydration or obstruction.
- Pouching systems: Pouching systems consist of a skin barrier (wafer) and a pouch. The wafer adheres to the peristomal skin and the pouch collects output. Proper fit prevents leakage and skin breakdown. Cut the wafer opening to match stoma size, no more than 1/8 inch larger than the stoma.
- Peristomal skin care: The skin around the stoma must be kept clean and dry. Use warm water and gentle cleansing; avoid alcohol-based products. Skin barriers and powders can protect against irritation. Monitor for rashes, excoriation, or infection. Allergies to adhesive materials may require specialized products.
- Dietary considerations: After ostomy surgery, patients may need dietary adjustments. For ileostomies, a low fiber diet initially, then gradually introduce foods. Chew thoroughly, drink adequate fluids, and avoid high fiber foods that can cause blockages. Colostomies may require bulk-forming foods to regulate output.
Terminology
- Stoma
- An opening created surgically to allow output from the intestine or urinary tract to exit the body.
- Ostomy
- Refers to the surgical procedure itself; the individual is called an ostomate.
- Lumen
- The hollow inside of the bowel through which contents pass.
- Mucocutaneous junction
- The border where the stoma mucosa meets the abdominal skin.
- Peristalsis
- Wavelike contractions that propel contents through the digestive tract.
Quick Revision
- The GI tract includes the small and large intestines, each with distinct roles in digestion and absorption.
- Stomas are created from ileum (ileostomy) or colon (colostomy), with specific anatomic locations.
- Blood supply and nerve function are essential for stoma health and motility.
- Key terms include stoma, ostomy, lumen, mucocutaneous junction, and peristalsis.
Disclaimer
Educational use only. Not intended for practical surgery, incisions, or other surgical procedures. It does not qualify you to perform physical operations.