Omentitis is mostly caused by various inflammations in the abdominal cavity. Common causes include subcutaneous nodular peritonitis, acute appendicitis, acute cholecystitis, acute pelvic inflammatory disease, diverticulitis, and peritonitis of various types, all of which can lead to inflammation of the greater omentum. In severe cases, late-stage [third-stage] adhesions may form. This acute inflammation generally subsides as the primary lesion heals. In addition, there is also idiopathic necrotic fat inflammation of unknown cause, also known as nonspecific lipitis.

bubble_chart Pathogenesis

The greater omentum is a double-layered peritoneal extension from the greater curvature of the stomach that hangs downward, covering the small intestine and colon. Near the pelvic brim, it folds back upon itself to form four layers of mesothelium over the transverse colon, though the central two layers fuse and gradually disappear during development. The size and fat content of the greater omentum are highly variable, with rich blood circulation and highly absorptive and anti-infective capabilities in its surface cells. It possesses rapid repair abilities through cell proliferation, fibrous tissue formation, and adhesion. The areolar tissue of the omentum is rich in macrophages, enabling it to quickly remove bacteria or carbon particles injected into the peritoneal cavity, which can later be observed within phagocytes in the omental mesothelium. The omentum can adhere to sites of inflammation or perforation, and foreign bodies in the peritoneal cavity, such as bullets or gauze pads, are often completely enveloped by the greater omentum. However, the greater omentum is not always beneficial. Due to its physiological and anatomical characteristics, it can also cause certain diseases, though rarely, including torsion, cysts, infarction, and occasionally tumors. Inflammation usually results from the spread of adjacent organ inflammation and rarely occurs independently.

The pathological changes involve aseptic necrosis of the omental adipose tissue, presenting as nodular thickening and shrinkage, which may form masses and adhere to surrounding tissues.

bubble_chart Clinical Manifestations

Various inflammatory diseases causing peritonitis often present with significant and distinctive manifestations. The main symptom of peritonitis is abdominal pain, typically chronic persistent or paroxysmal dull discomfort, which may be accompanied by digestive disorders such as abdominal distension, fullness, and loss of appetite. The pain is often localized in the right abdomen. After adhesion formation, it may lead to spasmodic abdominal pain, abdominal distension, fullness, nausea, and other symptoms of incomplete obstruction, as well as a sensation of intra-abdominal pulling. Local tenderness or a poorly defined mass with tenderness may also be palpable.

bubble_chart Diagnosis

Diagnosis is relatively difficult, as mild cases are often masked by the primary lesion. Patients with a history of peritonitis who currently present with symptoms of obstruction such as abdominal distension and fullness, abdominal pain, nausea, vomiting, and abdominal masses should be considered for this condition. Auxiliary X-ray contrast imaging may appear normal or show intestinal adhesions.

bubble_chart Treatment Measures

Patients with mild symptoms should consume low-fiber foods and avoid overeating or drinking to alleviate symptoms. For those with obstructive symptoms who show poor response to medical treatment, surgical intervention is recommended.