Jejunal diverticular disease: A gastrointestinal bleeding enigma

Figure 1 Complex interaction of different elements in the development and progression of diverticular disease. The triggering element is chronic increased intraluminal pressure. Sustained mechanical stress leads to structural alterations in the intestinal wall, including decreased collagen I/III ratio and excessive collagen fiber cross-linking. Concurrently, upregulation of matrix metalloproteinase 1 promotes degradation of fibrillar collagens, further weakening the submucosa and muscularis layers. These changes weaken wall compliance and favor mucosa and submucosa herniation through the muscularis propria, especially where marginal arteries penetrate the intestinal wall. MMP-1: Matrix metalloproteinase-1.