The transverse colon is a segment of the large intestine that processes digested food material from the small intestine. This muscular tube absorbs water and salts, contributing to the formation of solid waste.
Where is the Transverse Colon Located?
The transverse colon is situated horizontally across the upper abdomen. It extends from the right side of the body, where it connects to the ascending colon at the right colic flexure (also known as the hepatic flexure), to the left side, where it turns sharply downward to become the descending colon at the left colic flexure (or splenic flexure). This segment is the longest and most mobile part of the colon, measuring over 18 inches (46 cm).
Its position can vary, sometimes dipping lower into the pelvis, particularly in taller or thinner individuals. The transverse colon is almost entirely covered by the peritoneum, a membrane lining the abdominal cavity, and is suspended by a fold of this membrane called the transverse mesocolon. This mesocolon connects it to the inferior border of the pancreas. The transverse colon interacts spatially with other organs, with its upper surface relating to the liver, gallbladder, stomach, and spleen, while its lower surface is near the small intestine.
What Does the Transverse Colon Do?
The transverse colon continues processing indigestible food material. It absorbs a substantial amount of water and electrolytes, such as sodium and chloride, from the remaining liquid waste, solidifying the stool for elimination.
Beyond water absorption, the transverse colon hosts a diverse population of gut bacteria, forming part of the microbiome. These microorganisms ferment undigested carbohydrates and other residual substances, producing beneficial short-chain fatty acids and some vitamins. The colon’s muscular contractions, known as peristalsis, move the material back and forth, ensuring thorough mixing and absorption. This action, combined with mass movements, propels the forming stool towards the descending colon.
Common Issues Affecting the Transverse Colon
The transverse colon can be affected by various conditions. Diverticulitis, an inflammation of small, bulging pouches called diverticula, can occur in the transverse colon, though it is less common here than in other segments, accounting for less than 6% of all gastrointestinal diverticula. Symptoms include abdominal pain, which can be sharp and localized.
Inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis can also impact the transverse colon. Crohn’s disease can affect any part of the digestive tract, including the colon, leading to inflammation that can penetrate deeper layers of the intestinal wall. Ulcerative colitis primarily causes inflammation of the colon’s inner lining, often starting in the rectum and extending upwards, potentially involving the transverse colon in more extensive cases.
Colon polyps, which are growths on the inner lining of the colon, can develop in the transverse colon. While most polyps are benign, some have the potential to become cancerous over time. Colon cancer in the transverse colon may initially present with non-specific symptoms like abdominal discomfort, changes in stool consistency, or fatigue. More pronounced symptoms can include changes in bowel habits, rectal bleeding, or unexplained weight loss.