Histological examination of the lower margin of the internal sphincter has demonstrated an increased amount of fibrous tissue in patients with haemorrhoids compared with controls. This finding may be of relevance to the treatment of haemorrhoids by maximal anal dilatation.

A non-healing peri-anal abscess can be difficult to manage and is often attributed to chronic disease. This case documents a male in his seventh decade who presented with multiple peri-anal collections. The abscess cavity had caused necrosis of the internal sphincter muscles resulting in faecal incontinence. Biopsies were conclusive for diffuse large B-cell lymphoma. A de-functioning colostomy ...

The distribution of regulatory peptides was studied in the separated mucosa, submucosa and muscularis externa taken at 10 sampling sites encompassing the whole human sigmoid colon (five sites), rectum (two sites), and anal canal (three sites). Consistently high concentrations of VIP were measured in the muscle layer at most sites (proximal sigmoid: 286 (16) pmol/g, upper rectum: 269 (17), a mod...

The most distal part of the circular muscle layer functions as the internal anal sphincter, which constitutes a high pressure zone at rest, but maintains a relaxed state during defecation. To elucidate such sphincter mechanisms of the smooth muscle cells, the circular muscle layer in the canine anal canal was examined within 2 cm from the anal verge. Both the mechanical and intracellular electr...

Anorectal manometry measures the pressures of the anal sphincter muscles, sensation in rectum, and the neural reflexes that are needed for normal bowel movements. This test is mainly performed to evaluate patients with constipation or fecal incontinence but is also useful for pre/post surgical evaluation of anal sphincter tone, functional anorectal pain, pelvic floor dyssynergia and diagnosis o...

OBJECTIVES The aim of this study was to construct an anatomically correct phantom for visualization of anal sphincter complex structures. METHODS To ake an endoanal ultrasound phantom, we experimented with a variety of commercially available materials to simulate hyperechoic, hypoechoic, and isoechoic tissue consistency. We created external anal sphincter muscle and the levator plate using st...

Anal fistulas occurring in Crohn's disease (CD) comprise a risk factor of severe course of inflammation. They are frequently intractable due to various factors such as penetration of the anal canal or rectal wall, impaired wound healing, and immunosuppression, among others. Anal fistulas typical to CD develop from fissures or ulcers of the anal canal or rectum. Accurate identification of the ty...