Can you tell me which is the name of that disease where you lose a big part of your intestine?

Many conditions: One can lose a large part of the small intestine if it is removed because of crohn's disease. A large segment of small bowel might be removed if there is intestinal infarction due to mesenteric ischemia (arterial or venous) or if there is necrosis of the small bowel due to intestinal obstruction or intussusception. A large part of the colon may removed if there is a volvulus, colitis or cancer.

Indication 4 surgery: Removal of part of the small or large intestine may be necessary in cases of tumors, fixed strictures or obstructions, complicated diverticulitis, any enteritis or colitis that proves refractory to medical management, gangrenous gut (infectious, ischemic, unrelieved volvulus), malrotation, internal or external hernias, appendicitis, complicated punctures or blow-outs, just to name a few...