Sigmoid Neoplasms: Tumors or cancer of the SIGMOID COLON.Colon, Sigmoid: A segment of the COLON between the RECTUM and the descending colon.Sigmoid Diseases: Pathological processes in the SIGMOID COLON region of the large intestine (INTESTINE, LARGE).Intestinal Volvulus: A twisting in the intestine (INTESTINES) that can cause INTESTINAL OBSTRUCTION.Diverticulitis, Colonic: Inflammation of the COLONIC DIVERTICULA, generally with abscess formation and subsequent perforation.Diverticulum, Colon: A pouch or sac opening from the COLON.Cranial Sinuses: Large endothelium-lined venous channels situated between the two layers of DURA MATER, the endosteal and the meningeal layers. They are devoid of valves and are parts of the venous system of dura mater. Major cranial sinuses include a postero-superior group (such as superior sagittal, inferior sagittal, straight, transverse, and occipital) and an antero-inferior group (such as cavernous, petrosal, and basilar plexus).Colostomy: The surgical construction of an opening between the colon and the surface of the body.Intestinal Perforation: Opening or penetration through the wall of the INTESTINES.Pancreatic Neoplasms: Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Colectomy: Excision of a portion of the colon or of the whole colon. (Dorland, 28th ed)Mesocolon: The fold of peritoneum by which the COLON is attached to the posterior ABDOMINAL WALL.Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Colonoscopy: Endoscopic examination, therapy or surgery of the luminal surface of the colon.Colonic Diseases: Pathological processes in the COLON region of the large intestine (INTESTINE, LARGE).Neoplasms, Cystic, Mucinous, and Serous: Neoplasms containing cyst-like formations or producing mucin or serum.Neoplasms, Multiple Primary: Two or more abnormal growths of tissue occurring simultaneously and presumed to be of separate origin. The neoplasms may be histologically the same or different, and may be found in the same or different sites.Rectum: The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.Skin Neoplasms: Tumors or cancer of the SKIN.Appendiceal Neoplasms: Tumors or cancer of the APPENDIX.Colon: The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.Colonic Neoplasms: Tumors or cancer of the COLON.Intestinal Fistula: An abnormal anatomical passage between the INTESTINE, and another segment of the intestine or other organs. External intestinal fistula is connected to the SKIN (enterocutaneous fistula). Internal intestinal fistula can be connected to a number of organs, such as STOMACH (gastrocolic fistula), the BILIARY TRACT (cholecystoduodenal fistula), or the URINARY BLADDER of the URINARY TRACT (colovesical fistula). Risk factors include inflammatory processes, cancer, radiation treatment, and surgical misadventures (MEDICAL ERRORS).