HARWOOD, Justice.
John Olyn Tabor, Jr., petitioned this Court for a writ of certiorari to review the judgment of the Court of Civil Appeals affirming the trial court's order requiring Tabor to pay child support and postminority support pursuant to Ex parte Bayliss, 550 So.2d 986 (Ala.1989). We granted Tabor's petition to consider whether the Court of Civil Appeals correctly affirmed the trial court's judgment in light of Tabor's arguments that the doctrines of equitable estoppel, judicial estoppel, or res judicata prevented Tresa Livingston Tabor Buxton, Tabor's former wife, from claiming child support and postminority support under Bayliss, supra. We affirm in part, reverse in part, and remand.
The trial court, in a March 10, 2000, order entered after an ore tenus hearing, set out the underlying facts of this action, as follows:
"[Tabor and Buxton] were divorced in 1983 and entered into a Separation Agreement which was attached to the original Divorce Decree. At that time [Buxton] was awarded the care, custody, and control of the minor children of the parties, [a son and a daughter].
"... [Visitation] with [the minor children and Tabor] went well until the Fall of 1992. During December, 1992, [Tabor] filed a Petition for Rule Nisi, Petition for Modification or in the Alternative, Petition for Custody of the minor children.... [I]t was at this time that the relationship between the parties deteriorated and that the relationship between the minor children and [Tabor] deteriorated as well.
"... [Buxton] attempted to seek the Court's assistance in payment of child support from [Tabor], but was unsuccessful in obtaining an Order from the Circuit Court or the District Court of Dallas County, requiring the support to be paid by [Tabor].
"Finally, in December, 1993, almost 12 months after the filing of the Rule Nisi Petition, the Circuit Court rendered an Order signed by then Acting Circuit Judge William A. Ryan, indefinitely suspending the parental rights and responsibilities of [Tabor], forgiving the child support arrearage if any existed, and further suspending the obligation of support by [Tabor] to the minor children."
The December 10, 1993, order that suspended Tabor's parental rights and responsibilities and his obligation to pay child support for his minor children stated:
"This Court in continuing this case for trial confirms the pendente lite agreement of the parties reached during a prior assignment of this case and in so doing finds and ORDERS the following:
"1. That as of the time of the filing of the petition in this cause, neither party is indebted to the other party for child support.
"2. That the parental rights and responsibilities of [Tabor] are indefinitely suspended in view of the extreme deterioration of the relationship of the parties and the desire of this Court to preserve any remaining opportunities to restore the erstwhile good relations between the parties.
"3. Nothing in this Order shall prevent the voluntary undertaking and support and visitation by the parties, but none shall be prescribed by this Court pendente lite.
"4. A copy of this Order shall be filed by the Clerk in Dallas County Case No. DR-83-179.02 to allow that Court to know that this `.01' proceeding remains pending before this Court, thereby depriving such Court of any jurisdiction in this matter as claimed in a subsequently filed `.02' proceeding.
"5. At the request of Mr. Faile, counsel for [Buxton], this matter is continued for the first term of this Court, 1994."
On August 10, 1995, the trial court entered an amended order that stated:
"THIS CAUSE, having come before the Court upon the parties' Motion to Deem the Pendente Lite Decree a Final Order, and the same having been considered by the Court, it is
"ORDERED, ADJUDGED, and DECREED that the Pendente Lite Decree previously entered by this Court dated the [10th] day of December, 1993, shall be deemed a Final Order, and that the above-captioned matter shall be removed from the Administrative Docket."
On June 24, 1999, Buxton filed a complaint against Tabor seeking child-support payments and postminority support for their daughter, who was 18 years old at the time. Their oldest child, a son, had already reached the age of majority. The complaint stated, in pertinent part:
"2. That heretofore by that certain Divorce Decree dated August 9, 1983, the parties hereto were divorced and in said Decree [Tabor] was Ordered to pay certain sums in child support. That by virtue of that certain Pendente Lite Order dated December [10], 1993, the parental rights and responsibilities of [Tabor] were indefinitely suspended, but a further part of said Order stated that the parties were not prevented from the [voluntary] undertaking of support and visitation. This Pendente Lite Order was made a final Order on August 10, 1995. The minor children were not represented by a Guardian Ad Litem in any of said Orders."
Buxton's complaint also requested the following relief:
"1. That this Court will appoint a Guardian Ad Litem to represent the interest of [the son] and [the daughter] in this cause.
"2. That this Court will determine whether or not the Pendente Lite Order relieving [Tabor] from paying child support is valid as to the children because they were not represented by a Guardian Ad Litem and on the determination of that issue, will decide whether or not past due child support is ordered at this time.
"3. That this Court will Order [Tabor] to pay child support for [the daughter] until she attains the age of nineteen years, or dies, or marries, or becomes self sustaining, and in that event, child support payments as to that child shall cease and terminate.
"4. That this Court will determine that [the daughter] has the aptitude and ability to attend college, and will Order [Tabor] to pay a portion of said college educational expenses under the law set forth in the Bayliss case of the State of Alabama.
"5. Should [Buxton] be mistaken in the relief prayed for, that [she] be granted such other, further, different and general relief to which [she] may be entitled under the facts and the law of this case."
On September 1, 1999, Tabor filed an answer that stated, in pertinent part:
"3. [Tabor] answers that both the pendente lite order of December 17, 1993[sic], and the Final Order of August 10, 1995, were put forward to the Court by [Buxton] who had sought to terminate the rights and responsibilities of [Tabor] regarding the then minor children of the parties. [Buxton], while represented by very competent counsel, put forward to this Court both the pendente lite order and the final order of support which for all practical purposes granted [Buxton]'s wish that [Tabor] end his association with his minor children at the request of [Buxton] and [at] the request of the minor children of the parties who met in camera with the Judge presiding in such case who in all respects protected the interests of the minor children of the parties in lieu of a guardian ad litem.
"4. [Tabor] further answers that he was at all times opposed to this [disassociation] and that [Buxton] insisted upon the same and was relentless in her pursuit thereof.
"5. [Tabor] further answers that [Buxton] is estopped from asserting that claim made under the terms of this Complaint. She has—in all probability—permanently interrupted the father/child relationship as she sought to do in the prior proceeding involving these parties and their minor children and now that such has been fully accomplished, she seeks to impose responsibilities upon [Tabor] which he cannot bear.
"....
"7. Further, [Tabor] answers that he cannot afford to contribute to the college education of the [daughter] in that he is the sole supporting parent of six children including four children who have special and/or multiple needs....
"8. [Tabor] further answers that despite [Buxton]'s offer to `do equity' that she has not done so and could have reasonably anticipated that [Tabor] having been `shut away' from the children that he fathered by [Buxton] would seek to remarry and act as a good and proper father to the children now in his care, custody and control."
On January 21, 2000, the trial court conducted a hearing on Buxton's complaint. On March 6, 2000, it entered an order that contained the following findings:
"The Court, based upon the testimony of the parties and the law as submitted to the Court by the attorneys, finds that the Court Order of December [10,] 1993, wherein [Tabor]'s parental rights and responsibilities were indefinitely suspended, and further forgiving [Tabor] of any obligation of support in the future or for arrearage, is due to be set aside. This Court would cite the case of State ex rel. Donald Shellhouse v. Wanda Bentley, 666 So.2d 517[, 518] (Ala.Civ. App.1995), wherein the Court stated that,
"`The waiver of rights of visitation in exchange for release from the duty of child support is a legal impossibility.'
"Willis v. Levesque, 402 So.2d 1003, 1004 (Ala.Civ.App.1981).
"The Court further stated,
"`Parental support is a fundamental right of all minor children. It is a continued right, which cannot become stale until after the child reaches the age of majority. The right of support is inherent and cannot be waived, even by agreement.'
" The Court went on to state in Shellhouse that,
"`The custodial parent cannot agree to forgive the amount due under a child support arrearage, and the parent cannot waive child support due under a court order.'
"
"The Court finds that the Order of December 10, 1993, is in violation of these basic rules of law regarding child support and the parental obligations. However, the Court finds that
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