Anorectal malformations (ARMs) are one of the most common birth defects. They range from relatively simple defects to complex aberrations with serious functional consequences. Their prodigious variation and complexity make many aspects of the care of these conditions particularly challenging in low- and middle-income countries (LMICs), where they cause considerable suffering among affected patients, which may be debilitating and sometimes lifelong. This fact was acknowledged in 1959 by the American surgeon WJ Potts, whose oft-invoked anecdote: "a properly functioning rectum is an unappreciated gift of the greatest price", remains true to this day. Five billion people lack access to surgical care in LMICs, where cultural, social, health system and economic factors contribute to making the care of ARM in these countries a uniquely difficult prospect.

A recent bibliographic analysis of ARM literature confirmed that literature from LMICs was still sparse even amid the recent explosion of publications on the subject, and LMICs were largely absent from large research collaboratives or consortia on ARM [1,2].

This article explores ARMs from a global surgery lens. Using published literature and drawing from unpublished experience, we explore the epidemiology, clinical features, management, and outcomes of this disease, taking particular note of the unique challenges encountered in LMICs.

ARM is one of the most common congenital anomalies managed in LMICs and is the leading cause of intestinal obstruction in the neonatal period in many LMICs globally [3,4,5,6,7,8]. It also accounts for a considerable part of the pediatric operative workload in hospitals around the world and is one of the most common causes of childhood surgical death [5,6]. A recent survey [April/May 2023] of Global Initiative for Children's Surgery [GICS] congenital anomaly group on common birth defects in clinical practice, more than 70% responders found ARM [from 34 countries] is the common birth defect seen in their practice [unpublished data].

The oft-quoted frequency of ARM is an incidence of 1 in 5000 live births that was derived from a study in 1985 by deVries and Cox that predictably did not provide a comprehensive assessment of global incidence and requires updating [7].The true incidence of ARM is difficult to obtain in LMICs because of the lack of formal birth defect registries in these countries [9], the inaccuracy of birth registrations and the fact that many reports are hospital-based [7]. The best available population-based estimates from LMICs come from upper-middle-income countries such as Thailand, where the birth prevalence is 2.54 cases per 10 000 births [10], from Colombia: 2.2 per 10,000 [11] and from South Africa: 1.79/10,000 live births in the Western Cape region [12] and 2.5/10,000 live births in the Gauteng region [13]. No estimates are available for low-income countries. Current efforts may likely underestimate the true burden because of factors such as stigma, and low accessibility to the health system. The prevalence may also be higher in LMICs because of potential, as yet elusive nutritional deficiencies, environmental risk factors, teratogens and intrauterine infection.

Notwithstanding the inconsistent use of classification systems in earlier reports, patterns of common ARM subtypes appear similar to those in HICs [14]; however, several lesions are very infrequently encountered, especially in some parts of the world, while being common in others. At the Krickenbeck conference (26 international authorities on congenital malformations of the organs of the pelvis and perineum) in 2005 developed a system for comparable follow-up studies where the rare/ regional anomalies were grouped and acknowledged separately [1] and comprise congenital pouch colon, rectal atresia/stenosis, rectovaginal fistulas, H-type fistulas, and others. These lesions are said to be more commonly reported in some LMICs, such as in India and other Asian countries, than in Western, high-income countries [15]. Case reports and series abound of unusual cases, including congenital double anus with hindgut duplication, cloacal malformation variant in males, pouch colon and H Type malformation [16,17] from this part of the world. Other variants identified in a recent systematic review include H-type fistula with perineal fistula, perineal groove, H-type sinus, H-type canal, and acquired H-type fistula [18]. The steady stream of these subtly different variants continues to challenge the idea of a unified management approach to all malformations and emphasizes the importance of careful, thorough clinical examination with probing of the neonatal perineum.