Gastric bypass surgery is a weight loss operation conducted to help obese patients lose weight, according to MayoClinic.com. Gastric bypass surgery makes the stomach smaller and enables food to bypass part of the small intestine to decrease the absorption of food. Weight loss results when less food is absorbed. Formation of an internal hernia is a complication of gastric bypass.
Patients may experience fatigue symptoms after gastric bypass surgery due to low levels of blood and low levels of vitamin B12, according to MedlinePlus. Patients who undergo gastric bypass surgery lose blood containing red blood cells, resulting in anemia. Fatigue is one symptom of anemia. Patients become tired easily due to the lack of enough oxygenation of tissues. The reduction of the size of the stomach may cause a decrease in the amount of vitamin B12 absorbed by the stomach resulting in pernicious anemia. Vitamin B12 is required for proper red blood cells formation.
Patients with internal hernia after gastric bypass surgery may also experience fatigue due to abdominal pain. Internal hernia causes pain, discomfort and a localized swelling on the surface of the stomach, according to BariatricTimes.com. Patients who experience severe abdominal pain should seek medical attention.
Patients with internal hernia after gastric bypass may experience small bowel obstruction, according to BariatricTimes.com. The protruded intestines block the normal movement of food through the digestive tract. Patients may experience fatigue when the internal hernia and bowel obstruction prevent normal absorption of nutrients. Bowel obstruction is a medical emergency that requires immediate intervention. Signs of bowel obstruction include constipation and enlarged hard-like abdomen.
Vitamin and Mineral Deficiency
Patients who have undergone gastric bypass may also experience fatigue due to vitamin and mineral deficiency caused by nausea and loss of appetite, according to MayoClinic.com. Patients who have had gastric bypass may also experience a condition known as "dumping syndrome," which can lead to further malnutrition and fatigue. Dumping syndrome, also called "rapid gastric emptying," occurs when digested contents of the stomach are dumped into the small intestines too rapidly. This leads to symptoms, such as abdominal cramps, nausea, malnutrition and fatigue. Most patients with dumping syndrome may experience symptoms soon after eating.