Sigmoid colon and rectal tumors cause colonic obstruction much earlier in their development because the colon is narrower and the stool is harder in that area. Large bowel obstruction prior to perforation Obstruction that dilates the colon causes vague, visceral abdominal cramps. Pain receptors sense distention or vigorous contraction. Peritonitis may ensue. When giving a history of obstipation, patients may state that pants or belts are not fitting properly.
Intervention is necessary to prevent perforation.
Obstruction secondary to intussusception Patient may describe intermittent, crampy abdominal pain that is colicky and relieved by assuming fetal position. Weight loss and fatigue are common. Pneumaturia, mucinuria, or fecaluria may occur when fistulization of the sigmoid colon to the bladder occurs secondary to diverticulitis or cancer. Bowel sounds may be normal early on but usually become quiet. Abdomen is hyperresonant to percussion.