The endocrine system encompasses a group of organs and body tissues that secrete chemicals called hormones, which influence the activity of other body tissues. Various hormones help regulate digestive tract activity. Disorders that affect the levels of these hormones can cause accelerated transit time through the intestines, leading to weight loss and loose stools.
Addison's disease is a condition characterized by progressive failure of the adrenal glands, specifically the outer region of the glands known as the adrenal cortex. This region of the adrenal glands produces and secretes several important hormones, including cortisol and aldosterone. With Addison's disease, the levels of both cortisol and aldosterone prove abnormally low.
Patients with Addison's disease often experience diarrhea and weight loss, notes "The Merck Manual for Healthcare Professionals." Other common symptoms include fatigue, skin darkening and freckling, nausea, vomiting, dizziness, cold intolerance and dehydration. Treatment focuses on correction of the hormone deficiencies with cortisol and aldosterone replacement therapy.
Graves' disease is an autoimmune disorder affecting the thyroid gland. With this condition, the immune system mistakenly targets the thyroid gland and produces antibodies that stimulate overproduction and release of the thyroid hormones, explains the American Thyroid Association. Graves' disease is the most common type of overactive thyroid disease, or hyperthyroidism.
The excess thyroid hormones associated with Graves' disease cause a variety of symptoms, including frequent bowel movements and weight loss. Frank diarrhea may occur in some patients. Other possible symptoms of Graves' disease include nervousness, insomnia, irritability, hand tremors, excessive sweating, heat intolerance, weakness and heart palpitations. Treatment involves antithyroid medication to reduce production of the thyroid hormones.
Thyroiditis describes a painful inflammation of the thyroid gland. With this condition, the thyroid gland releases excessive amounts of the thyroid hormones into the circulation. The symptoms associated with thyroiditis prove similar to those caused by Graves' disease and other types of hyperthyroidism, and include increased bowel movement frequency, weight loss and possible diarrhea. Thyroid tenderness often proves a distinguishing characteristic of thyroiditis. Thyroiditis usually resolves spontaneously, although patients may experience a period of abnormally decreased thyroid gland activity before the thyroid hormone levels normalize, reports the American Association of Clinical Endocrinologists.
Zollinger-Ellison syndrome is an uncommon disorder characterized by endocrine tumors known as gastrinomas. These tumors secrete excessive amounts of the hormone gastrin, which leads to overproduction of stomach acid, reports the National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms of Zollinger-Ellison syndrome include abdominal pain, severe heartburn, nausea, vomiting, diarrhea and weight loss. Treatment with medications called proton pump inhibitors help control the overproduction of stomach acid. Doctors may recommend surgical removal of the tumors, if feasible.