Colon Polyps : Clinical Features
Clinical Features: Most patients with colonic polyps have no symptoms referable to the GI tract or have only non-specific intestinal symptoms. However, polyps can ulcerate due to friction against fecal matter and cause occult or overt rectal bleeding. Polyps smaller than 1 cm usually do not bleed. Only polyps larger than 1.5 to 2.0 cm cause any significant blood loss. Fecal occult blood loss leading to anemia is less commonly seen with polyps than with colon cancer.
Peristaltic waves may push the polyp downstream stretching its blood vessels and nerve supply producing abdominal pain. Larger polyps have been known to cause intestinal obstruction or intussusception which can present with acute abdominal pain. Constipation or decreased caliber of stool may be seen with bulky tumors in the distal colon. Diarrhea and flatulence are additional symptoms.
Rare cases of large villous adenomas (usually > 3-4 cm) in the rectum or rectosigmoid can cause secretory diarrhea leading to dehydration and electrolyte imbalances. They secrete large quantities of protein and potassium into the gut lumen most of which has no opportunity for reabsorption and is excreted causing hypoproteinemic hypokalemia.