Why do Diverticula get Infected?
Diverticula, those small pouches in the colon wall, aren't inherently problematic when they are just present (a condition called diverticulosis). However, several factors can lead to them becoming infected, resulting in diverticulitis. Here's a breakdown of the main reasons why diverticula can get infected:
The Key Factor: Stool and Bacteria Trapped in the Pouches
The primary reason diverticula become infected is the entrapment of stool and bacteria within these pouches. Here's how it happens:
Formation of Pouches: Diverticula themselves are outpouchings in the colon wall. Their very structure creates little sacs or pockets that are somewhat isolated from the main flow of waste through the colon.
Stool and Debris Accumulation: Because of their pouch-like shape, diverticula can trap small amounts of stool, undigested food particles, and bacteria as waste material passes through the colon.
Bacterial Overgrowth: The trapped material becomes stagnant and provides a breeding ground for bacteria that are naturally present in the colon. This can lead to an overgrowth of bacteria within the diverticulum.
Contributing Factors that Increase Infection Risk:
While trapped stool and bacteria are the direct cause, several other factors can increase the likelihood of this happening and progressing to infection:
Low-Fiber Diet: A diet lacking in fiber contributes to smaller, harder stools. These smaller stools can more easily get lodged in diverticula and increase pressure within the colon, potentially pushing more material into the pouches. (However, it's worth noting that some recent research, as indicated in the search snippet, suggests the link between low fiber and constipation, and by extension, diverticulitis, might be more complex than previously thought).
Increased Pressure in the Colon: Anything that increases pressure within the colon can make it easier for stool and bacteria to get forced into diverticula. This pressure can be caused by:
Straining during bowel movements: Often linked to constipation.
Irregular bowel habits: Inconsistent bowel movements can lead to pressure fluctuations.
Obesity: Excess weight can put pressure on the abdominal area and colon.
Weakened Colon Wall: As we age, the colon wall can naturally weaken. This weakening may make it easier for diverticula to form and potentially make them more susceptible to trapping material.
Inflammation and Erosion: The trapped material and bacterial overgrowth can irritate the lining of the diverticulum. This irritation can lead to:
Inflammation: The diverticulum wall becomes inflamed (diverticulitis).
Erosion: In severe cases, the inflammation can erode the diverticulum wall, potentially leading to a small tear (microperforation).
Perforation (Tear) and Leakage: If the inflammation and erosion worsen, it can lead to a more significant tear in the diverticulum wall (perforation). This allows bacteria and infected material to leak out of the colon and into the surrounding tissues of the abdomen. This leakage is what causes the more serious complications of diverticulitis, such as:
Abscess formation: A localized collection of pus and infection.
Peritonitis: Inflammation of the peritoneum, the lining of the abdominal cavity, a serious and potentially life-threatening condition.
In summary: Diverticula get infected when stool and bacteria become trapped in the pouches, leading to bacterial overgrowth, inflammation, and potentially perforation. Factors like low-fiber diet, increased colon pressure, and a weakened colon wall can increase the risk of this process occurring.