Tests may include CBC (complete blood count), thyroid function tests, serum calcium, serum potassium, etc.Abdominal X-rays are generally only performed if bowel obstruction is suspected, may reveal extensive impacted fecal matter in the colon, and may confirm or rule out other causes of similar symptoms.Colonoscopy may be performed if an abnormality in the colon like a tumor is suspected. Other tests rarely ordered include anorectal manometry, anal sphincter electromyography, and defecography.Colonic propagating pressure wave sequences (PSs) are responsible for discrete movements of the bowel contents and are vital for normal defecation. Deficiencies in PS frequency, amplitude, and extent of propagation are all implicated in severe defecatory dysfunction (SDD). Mechanisms that can normalize these aberrant motor patterns may help rectify the problem. Recently the novel therapy of sacral nerve stimulation (SNS) has been utilized for the treatment of severe constipation. Criteria
The Rome III Criteria for functional constipation must include two or more of the following and present for the past three months, with symptoms starting for at least 6 months prior to diagnosis. Straining during defecation for at least 25% of bowel movements
Lumpy or hard stools in at least 25% of defecations
Sensation of incomplete evacuation for at least 25% of defecations
Sensation of anorectal obstruction/blockage for at least 25% of defecations
Manual maneuvers to facilitate at least 25% of defecations
Fewer than 3 defecations per week
Loose stools are rarely present without the use of laxatives
There are insufficient criteria for irritable bowel syndrome

Prevention
Constipation is usually easier to prevent than to treat.
Risk factors that increase the risk of constipation in this population include:
Damage to the levator ani muscles (pelvic floor muscles) during childbirth
Forceps-assisted delivery
Lengthy second stage of labor
Delivering a large child
HemorrhoidsHemorrhoids are common in pregnancy and also may get exacerbated when constipated. Anything that can cause pain with stooling (hemorrhoids, perineal tear, episiotomy) can lead to constipation because patients may withhold from having a bowel movement so as to avoid pain.The pelvic floor muscles play an important role in helping pass a bowel movement. Injury to those muscles by some of the above risk factors (examples- delivering a large child, lengthy second stage of labor, forceps delivery) can result in constipation. Enemas may be administered during labor and these can also alter bowel movements in the days after giving birth. However, there is insufficient evidence to make conclusions about the effectiveness and safety of laxatives in this group of people. See also
Obstructed defecation
Rectal tenesmus

References
External links

09-129b. at Merck Manual of Diagnosis and Therapy Home Edition
Constipation - Introduction (UK NHS site)
MedlinePlus Overview constipation
Constipation Guideline - the World Gastroenterology Organisation (WGO)