The bowel sometimes forms loops, twisting around on itself to form an obstruction called a volvulus. Doctors classify volvulus into different types on the basis of where in the gastrointestinal tract the twisting occurs:
- Volvulus of the small intestine
- Volvulus of the cecum
- Sigmoid colon volvulus
- Volvulus of the transverse colon
- Volvulus of the splenic flexure
- Gastric volvulus
- Ileosigmoid knotting
The splenic flexure type, at a natural bend in the colon near the spleen, is the rarest kind of volvulus. The most common is in the S-shaped sigmoid colon near the bottom of the gastrointestinal passageway. Eating a single large meal rather than several smaller meals throughout the day, particularly over a period of time, can increase the likelihood of developing volvulus. All volvuli cause bowel obstruction and stop blood flow to the affected area, leading to gangrene. Left untreated, volvulus will gradually destroy the intestine due to buildup of fluid and lack of blood; the condition is eventually fatal.
Symptoms include abdominal pain, tenderness, and swelling; nausea and vomiting, occasionally with stool in the vomit; constipation or diarrhea; and fatigue. Treatment starts with a nasogastric tube, which is inserted through a nostril to suck out digested food in order to relieve pressure. Surgery is generally necessary to untwist the bowel, though except in severe cases, it can be done laparoscopically, through a small incision. However, if necrosis has occurred, open surgery is generally needed to remove the dead tissue.