In patients found to have RH on simple balloon distension, impaired perception of rectal distension may be partly explained in one subgroup by abnormal rectal compliance. However, a second subgroup exists with normal rectal wall properties, suggestive of a true impairment of the afferent pathway. The barostat has an important role in the identification of these subgroups of patients.

INTRODUCTION The development of pancreatic infection is associated with the development of a deteriorating disease with subsequent high morbidity and mortality. There is agreement that in mild pancreatitis there is no need to use antibiotics; in severe pancreatitis it would appear to be a logical choice to use antibiotics to prevent secondary pancreatic infection and decrease associated mortality. MATERIALS AND METHODS A non-systematic review of current evidence, meta-analyses and randomized controlled trials was conducted to assess the role of prophylactic antibiotics in acute pancreatitis and whether it might improve morbidity and mortality in pancreatitis. RESULTS Mixed evidence was found to support and refute the role of prophylactic antibiotics in acute pancreatitis. Most studies have failed to demonstrate much benefit from its routine use. Data from our unit suggested little benefit of their routine use, and showed that the mortality of those treated with antibiotics was significantly higher compared with those not treated with antibiotics (9% vs 0%, respectively, P = 0.043). In addition, the antibiotic group had significantly higher morbidity (36% vs 5%, respectively, P = 0.002). CONCLUSIONS Antibiotics should be used in patients who develop sepsis, infected necrosis-related systemic inflammatory response syndrome, multiple organ dysfunction syndrome or pancreatic and extra-pancreatic infection. Despite the many other factors that should be considered, prompt antibiotic therapy is recommended once inflammatory markers are raised, to prevent secondary pancreatic infection. Unfortunately, there remain many unanswered questions regarding the indications for antibiotic administration and the patients who benefit from antibiotic treatment in acute pancreatitis.

Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.

EP remains the first line investigation for the diagnosis of rectal intussusception, but may not distinguish mucosal from full-thickness descent. MR defaecography further complements EP by giving information on movements of the whole pelvic floor, 30% of the patients studied having associated abnormal anterior and/or middle pelvic organ descent. If surgery is planned for patients with rectal intussusception, MR defaecography provides useful information regarding the presence and degree of anterior pelvic compartment descent that may need to be addressed if a good functional outcome is to be achieved.