The causes of constipation can be divided into congenital, primary, and secondary. The most common kind is primary and not life-threatening. It can also be divided by the age group affected such as children and adults. Primary or functional constipation is defined by ongoing symptoms for greater than six months not due to an underlying cause such as medication side effects or an underlying medical condition. It is not associated with abdominal pain, thus distinguishing it from irritable bowel syndrome. It is the most common kind of constipation, and is often multifactorial. In adults, such primary causes include: dietary choices such as insufficient dietary fiber or fluid intake, or behavioral causes such as decreased physical activity. In the elderly, common causes have been attributed to insufficient dietary fiber intake, inadequate fluid intake, decreased physical activity, side effects of medications, hypothyroidism, and obstruction by colorectal cancer. Evidence to support these factors however is poor. Secondary causes include side effects of medications such as opiates, endocrine and metabolic disorders such as hypothyroidism, and obstruction such as from colorectal cancer or ovarian cancer. Celiac<unk>  and non-celiac gluten sensitivity may also present with constipation. Cystocele can develop as a result of chronic constipation. Diet Constipation can be caused or exacerbated by a low-fiber diet, low liquid intake, or dieting. Dietary fiber helps to decrease colonic transport time, increases stool bulk but simultaneously softens stool. Therefore, diets low in fiber can lead to primary constipation. Medications Many medications have constipation as a side effect. Some include (but are not limited to) opioids, diuretics, antidepressants, antihistamines, antispasmodics, anticonvulsants, tricyclic antidepressants, antiarrythmics, beta-adrenoceptor antagonists, anti-diarrheals, 5-HT3 receptor antagonists such as ondansetron, and aluminum antacids. Certain calcium channel blockers such as nifedipine and verapamil can cause severe constipation due to dysfunction of motility in the rectosigmoid colon. Supplements such as calcium and iron supplements can also have constipation as a notable side effect. Medical conditions Metabolic and endocrine problems which may lead to constipation include: pheochromocytoma, hypercalcemia, hypothyroidism, hyperparathyroidism, porphyria, chronic kidney<unk> , pan-hypopituitarism, diabetes mellitus, and cystic fibrosis. Constipation is also common in individuals with muscular and myotonic dystrophy. Systemic<unk> s that may present with constipation include celiac<unk>  and systemic sclerosis. Constipation has a number of structural (mechanical, morphological, anatomical) causes, namely through creating space-occupying lesions within the colon that stop the passage of stool, such as colorectal cancer, strictures, rectocoles, anal sphincter damage or malformation and post-surgical changes. Extra-intestinal masses such as other malignancies can also lead to constipation from external compression. Constipation also has neurological causes, including anismus, descending perineum syndrome, and<unk> 's<unk> . In infants,<unk> 's<unk>  is the most common medical disorder associated with constipation. Anismus occurs in a small minority of persons with chronic constipation or obstructed defecation. Spinal cord lesions and neurological disorders such as Parkinson's<unk>  and pelvic floor dysfunction can also lead to constipation. Chagas<unk>  may cause constipation through the destruction of the myenteric plexus. Psychological Voluntary withholding of the stool is a common cause of constipation. The choice to withhold can be due to factors such as fear of pain, fear of public restrooms, or laziness. When a child holds in the stool a combination of encouragement, fluids, fiber, and laxatives may be useful to overcome the problem. Early intervention with withholding is important as this can lead to anal fissures. Congenital A number of<unk> s present at birth can result in constipation in children. They are as a group uncommon with<unk> 's<unk>  (HD) being the most common. There are also congenital structural anomalies that can lead to constipation, including anterior displacement of the anus, imperforate anus, strictures, and small left colon syndrome.
symptom of Hirschsprung's disease
symptom of Necrotizing enterocolitis
symptom of Stomach cancer
symptom of Intussusception 
symptom of Small intestine cancer
symptom of Hiatal hernia
symptom of Ulcerative colitis
medical cause of Constipation