The development of the Internet services and applications and the trend in the fourth generation (4G) wireless networks to all-IP networks have led to a growing demand for enabling Mobile Ad hoc NETworks (MANETs) to connect to the Internet and achieving the goal of omnipresence Internet which is accessible anytime and anywhere. However, such integration gives rise to a number of challenges. In this paper, an efficient framework which has considered six main challenges encountered in the MANET-Internet integration is proposed. An adaptive distributed multipath internet gateways discovery protocol is proposed, where the gateways advertise their information dynamically to an adaptive limited number of mobile nodes. For mobile nodes that cannot receive this information, an efficient dynamic routing algorithm for MANETs-Internet integration derived from the ant colony optimization algorithms is proposed. In addition, an improved Quality of Services based gateway selection mechanism providing load-balancing is proposed. The simulation study confirms that the proposed framework is scalable and able to cope with changes on the number and mobility of active sources connecting to the Internet and outperforms other conventional approaches in terms of end-to-end delay, packet delivery ratio while attaining acceptable overhead and fair load distribution among all gateways.