Cap-assisted endoscopic sclerotherapy (CAES) is a new interventional therapy for internal hemorrhoids and rectal prolapse under colonoscopy. However, the long-term efficacy and safety of CAES in the treatment of internal hemorrhoids and rectal prolapse are still not clear due to the lack of large sample studies. Therefore, a nationwide multi-center, large sample, prospective and cohort study was designed to evaluate the efficacy and safety of CAES in the treatment of internal hemorrhoids and rectal prolapse, to provide reliable evidence for popularization of this minimally invasive technology.

CAES is an innovative endoscopic sclerotherapy procedure which is different from traditional method. Firstly, the cap added to the front of colonoscope can fully expose the operating field. Secondly, before or during the opportunity of CAES, endoscopist can perform endoscopic differentiation diagnosis (such as tumors, inflammatory bowel disease and others induced hematochezia), endoscopic therapy within lower-gut based on the same colon preparation, thus saving patients' medical cost, physical and mental pain. The last but not least, specially designed length of endoscopic injection needle (eg.10-20 mm) was used in CAES could be helpful for accurately controlling the injection angle, direction, depth under direct vision and to avoid iatrogenic injury due to ectopic injection.The core value of CAES for internal hemorrhoids and rectal prolapse is to provide precise therapy, reduce the iatrogenic injuries, avoid pain during and after therapy. Our pilot studies demonstrated that CAES based on long injection needle is an effective, safe, convenient operation technique. 100% of participants underwent CAES showed sustained clinical efficacy within the 3-month follow-up, with no severe or obvious complications related to CAES. However, the long-term efficacy and safety of CAES in the treatment of internal hemorrhoids and rectal prolapse need to be confirmed by further large sample real world studies.

Inclusion Criteria:

1. Grade I-III internal hemorrhoids (with or without external hemorrhoids) or/and recal prolapse.
2. Patients with bowel preparation.

Exclusion Criteria:

1. History of anoscopic/endoscopic sclerotherapy.
2. Acute thrombotic hemorrhoids or grade IV internal hemorrhoids.
3. Anal stenosis, perianal and perirectal abscess, anal fissure, fistula, fecal incontinence and other severe complications (such as severe anal pain).
4. Inflammatory bowel disease.
5. Full-thickness rectal prolapse through the anus.
6. Acute diarrhea in the past 24 hours.
7. Hypertensive with uncontrolled blood pressure.
8. Cerebrovascular accident.
9. Blood coagulation dysfunction.
10. Pregnant women.
11. Mental disorders.
12. Decompensated cirrhosis.

Grade I-III internal hemorrhoids and/or rectal prolapse