Change in caliber of stools strongly suggests carcinoma. When associated with weight loss, likelihood of carcinoma increases. Colonic lesion development history Right-sided colonic lesions can grow quite large before obstruction occurs because of the large capacity of the right colon and soft stool consistency. 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.