Anal tight stool can not pull, no strength, clinical possible causes are hemorrhoids, anal spasm, rectal contraction weakness. 1. hemorrhoids: people with the disease of the anal sphincter may be over-expanded, which leads to the muscle for the state of relaxation, or the relevant group of people older and the emergence of muscle atrophy, which may cause people with hemorrhoids to defecate difficult, defecation weakness and other symptoms. 2. anal spasm: this situation is mostly seen in people with anal fissure, the local lesion of the affected area will stimulate the anal sphincter muscle spasm, thus appearing defecation difficulty or defecation weakness. 3. Rectal contraction weakness: this situation is mostly seen in the weaker or chronic constipation of the population, which usually occurs in the colorectal innervating nerve fiber pathological changes, will also cause the people with related diseases defecation weakness and defecation difficulties. If the symptoms persist or have a tendency to worsen, it is recommended to go to the anorectal department of the hospital to receive targeted treatment after clarifying the cause of the disease.