The purpose of this study is to re-evaluate the therapeutic superiority and safety of acupuncture treatment using high quality and large sampled clinical research. Our objectives are to normalize the syndrome differentiation, point selection, technical procedure, and electric acupuncture parameters, which provide high level evidence-based proofs for acupuncture clinical treatments. We want to provide a preferred treatment protocol, which is effective, safe, and easy to use in clinical practice. This research also clarifies that the insertion depth is a key factor in the therapeutic effect of acupuncture. The results of our study will help promote the development of the standardization of acupuncture.

Functional constipation is a high morbidity disease. The life-long treatment of functional constipation can seriously impact a patient's quality of life. At present, the most frequently used treatment is catharsis, which deals with the symptom. This therapy is effective in the short-term for general functional constipation, whereas the effect is poor in colonic slow transit constipation. There are three main problems with catharsis. First, there are no long-lasting effects once the patient stops taking medication. Second, there are many side effects, including abdominal pain with defecation and diarrhea. Third, long-term use of irritant laxatives will not only make the constipation become refractory and complex; but also, this type of medicine can harm the enteric nervous system, cause melanosis coli, or even carcinoma of colon. Traditional Chinese Medicine diagnosis and treatment has its own advantages in treating functional constipation, but the therapeutic effect of treating colonic slow transit constipation is still uncertain. Although constipation is relieved to a certain extent, the patient also suffers from abdominal pain during defecation. Chinese herbs, such as Radix et Rhizoma Rhei, or Cassia angustifolia Vahl, are laxatives which also provide short-term effects. Long-term administration of the Chinese herbs will affect the regulation of Meissner's plexus, Auerbach's plexus, and gastrointestinal hormones, as well as make the digestive system depend on laxatives.

Therefore, a therapy that is safe with minimal side effects and good short-term and long-term effects is urgently needed in functional constipation treatment, especially for the type of slow colonic transit functional constipation.

Clinical practice shows that acupuncture meets this need. The acupuncture therapy is safe and effective especially for slow colonic transit functional constipation，and the therapeutic effects are still present several months after the treatment has been completed.

• Device: Deep needle on ST25 (bilateral) with electric stimulator
• Drug: Lactulose
• Device: Huatuo brand needle, LH202H electric stimulator

• Experimental:

  Deep needle on ST25 Tianshu (bilateral) with electric stimulator. Insert the needle (75 mm, Huatuo brand) vertically until it is 1 to 2mm into the peritoneum and the patient feels obvious dragging pain (which is about 1.8 to 2.5 cun) with no hand technique of the needle. Then put the electrode on the handle of the needle on both sides and the parameter is constant amplitude, 2/15Hz frequency, and the current intensity is adjusted to the abdominal muscles shiver slightly and the patient feels trivial pain. The abdomen circumference, the needle depth and the electric intensity of the first time treatment should be recorded as reference in the standardization.) Leave the needles for 30min.

  Once a day, five time a week, four weeks.

• Active Comparator: Lactulose oral solution, oral administration, 20-30ml The patient takes before breakfast. The treatment continues for four weeks.
• Other:

  Acupuncture: ST-25 Tianshu (bilaterally), 25 mm filiform needle (Huatuo brand, 30#), vertically, depth: 0.3 cun （, or 7.5 mm）; the acupuncture technique is superficial acupuncture and parameter of electric stimulator is the same as Group A.

  Course: once a day, five times a week, four weeks

Inclusion Criteria:

• Patients are diagnosed by specialists in the department of anus and intestine,or the department of gastroenterology according to the diagnostic criteria of functional constipation.
• Age between 18 to 75 years old
• Conscious, favorable general condition, cooperate with examination and treatment
• Hemiplegic patients due to stroke should be able to take care of themselves (Barthel Index≥50), and they can walk or use cane to walk 20m. And they are diagnosed as functional constipation before stroke.
• Volunteer to join this research and sign the written informed consent prior to receiving treatment
• Provide address and phone number, and cooperate with long-term follow-up

Exclusion Criteria:

• Irritable bowel syndrome, or constipation caused by tumor, inflammation, medication, endocrine, or metabolic diseases
• Age younger than 18 years old, or older than 75 years old
• Known serious cardiovascular disease, hepatic injury, or renal damage; serious cognitive dysfunction; aphasia, serious mental disorder; malnutrition, poor general condition, unable to cooperate with examination or treatment
• Pregnancy or breast-feeding woman
• Abdominal aneurysm, abnormal splenohepatomegaly, enteroparalysis, partial intestinal obstruction, celiac tuberculosis
• Coagulation disorders, or constantly use anticoagulant drugs, such as heparin
• Patients with cardiac pacemaker
• Patients who is seriously afraid of needles
• Patients who did not fill in constipation diary card in the baseline evaluation period, or not volunteer to join this research program
• No contact method, unable to cooperate with follow-up